meson error

# Conflicts:
#	include/builtins.h
#	include/data.h
#	include/editor_op.h
#	include/file_io.h
#	include/input.h
#	include/row_op.h
#	install.sh
#	main.c
#	meson.build
#	src/builtins.c
#	src/editor_op.c
#	src/file_io.c
#	src/init.c
#	src/input.c
#	src/output.c
#	src/row_op.c

.gitea/workflows/build.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   build:
-    runs-on: home-1
+    runs-on: giorgio-runner
 
     steps:
       - name: Checkout code

README.md

@@ -1,26 +1,32 @@
 # Beluga
 
-Beluga is a project of CLI text editor that will fit perfectly with your azerty keyboard.
+Beluga is a project of CLI text editor that uses lisp as configuration language.
 
 ## Requirements
 
-You will only need **cmake** and **clang** to compile the editor.
+You will only need **meson** and a **C compiler** to compile the editor.
 
 ## Installation
-
+### From source
 Here is the installation line for development version:
 
-```git clone --recurse-submodules https://github.com/le-cocotier/beluga.git ~/.beluga && cd ~/.beluga && mkdir build && cd build && cmake ../ && make beluga```
+```git clone https://git.giorgio-nas.fr/arthur/beluga.git && cd beluga && meson setup build && meson compile -C build```
 
-The executable file will be in `bin/beluga`. Feel free to add it to your path.
+The executable file will be `build/beluga`. Feel free to add it to your path.
 
-You can either run `make all` or `make doc_doxygen` if you're interested by the doxygen documentation.
+### From installation script ( prefered )
+
+Just clone the repo and execute the script `install.sh`. It will automatically add beluga to your path.
 
 ## Getting start
 
 To open an existing file just type :
-```beluga path_to_my_file```
+```./build/beluga path_to_my_file```
 
-The only keybinds that you will need will be :
- - Ctrl-Q : leave the editor
- - Ctrl-S : Save a file
+Here is some few command that you will need :
+
+| keybind       | command          |
+|---------------|------------------|
+| Ctrl-x Ctrl-c | leave the editor |
+| Ctrl-x Ctrl-s | Save a file      |
+| Ctrl-x f      | open file        |

assets/beluga.txt

@@ -1,43 +1,43 @@
                       **#%#*****###%**
-                *##+--------------------=##*  
-             #*=----------------------------=*#*                                 
-          #*------------------------------------*#                               
-        %+----------------------------------------=#*                            
-       #+---------------------------------------------##                            
-     *#-------------------------------------------------=##                         
+                *##+--------------------=##*
+             #*=----------------------------=*#*
+          #*------------------------------------*#
+        %+----------------------------------------=#*
+       #+---------------------------------------------##
+     *#-------------------------------------------------=##
     *#----------------------------------------------------:-##
-    #----------------------------------------------------------##                   
-   #=--------------------------------------------------------------##                
-  +--------------------------+@#-%*-----------------------------------#*         
-  +--------------------------%@@@@#-------------------------------------**                              BELUGA - VERSION 1.1
+    #----------------------------------------------------------##
+   #=--------------------------------------------------------------##
+  +--------------------------+@#-%*-----------------------------------#*
+  +--------------------------%@@@@#-------------------------------------**                              BELUGA - VERSION 2.4
   *-=-------------------------#@@*---------------------------------------=%
   %*#==--------------------------------------------------------------------+#                           ----- KEY-BINDS -----
-  *%%=-=--------------------------------------------------------------------=#                          CTRL-q         leave
-  %=--------------------------------------------------------------------------#*                        CTRL-s          save
- %-----------------------------------------------------------------------------**                       CTRL-o     open-file
-*+--=---===----=---------------=*-----------------------------------------------** 
- #--=##      *#%#*+==----==+**+----------------------=  ***=---------------------% 
- *%**=-----------====    ==---------------------------------=+#+-----------------=#                                 
-   *%=----------------------------------------------------------=#*---------------#                                 
-     ##=----------------------------------=------------------------+%=------------+#                                
-       #%+---------------------------------=*------------------------+%------------#                                
-         *#%*=-------------=-----------------#-------------------------#+----------#                                
-             **#%#*******+=======-------------#=------------------------#----------#                                
-                #===#*=======------------------#*----=-----------=--=##*-----------#                                
-                 -====##=------------------------*%+------------=*#+=====----------#                                
-                 --=====+#*=----------------------=-=+*#####***+=======-----------=*                                
-                %------=====*%*=-------------------------========-----------------+*                                
-                 *-=--------====%%###+=--------------------------=-----------------#                                
-                  #-----------=%        +*##%%%%%%@@%%%%####*==---------------------**                              
-                    %=-------#*                                  #%*=-----------------+#                              
-                     *%+--=##                                       ##=-----------------=#*                           
-                        **                                       #+----=-------------------#*                       
-                                                               %+----------------------------#*                     
-                                                             *%-------------==----------------+#                    
-                                                            ##--------------==------------------#                     
-                                                           *#--------------===%-----------------=%                  
-                                                          ##---------------=-##*-----------------+#                 
-                                                        *#---------------==#+=#%-----------------%                 
-                                                       *%---------------+#      %*---------------#*                  
-                                                      *#------------=+#*          #%*=-----------#*                  
-                                                       #****##******                 *#%%##+=----%                 
+  *%%=-=--------------------------------------------------------------------=#                          CTRL-x CTRL-c  leave
+  %=--------------------------------------------------------------------------#*                        CTRL-x CTRL-s   save
+ %-----------------------------------------------------------------------------**                       CTRL-x f   open-file
+*+--=---===----=---------------=*-----------------------------------------------**
+ #--=##      *#%#*+==----==+**+----------------------=  ***=---------------------%
+ *%**=-----------====    ==---------------------------------=+#+-----------------=#
+   *%=----------------------------------------------------------=#*---------------#
+     ##=----------------------------------=------------------------+%=------------+#
+       #%+---------------------------------=*------------------------+%------------#
+         *#%*=-------------=-----------------#-------------------------#+----------#
+             **#%#*******+=======-------------#=------------------------#----------#
+                #===#*=======------------------#*----=-----------=--=##*-----------#
+                 -====##=------------------------*%+------------=*#+=====----------#
+                 --=====+#*=----------------------=-=+*#####***+=======-----------=*
+                %------=====*%*=-------------------------========-----------------+*
+                 *-=--------====%%###+=--------------------------=-----------------#
+                  #-----------=%        +*##%%%%%%@@%%%%####*==---------------------**
+                    %=-------#*                                  #%*=-----------------+#
+                     *%+--=##                                       ##=-----------------=#*
+                        **                                       #+----=-------------------#*
+                                                               %+----------------------------#*
+                                                             *%-------------==----------------+#
+                                                            ##--------------==------------------#
+                                                           *#--------------===%-----------------=%
+                                                          ##---------------=-##*-----------------+#
+                                                        *#---------------==#+=#%-----------------%
+                                                       *%---------------+#      %*---------------#*
+                                                      *#------------=+#*          #%*=-----------#*
+                                                       #****##******                 *#%%##+=----%

config/init.lisp

@@ -2,6 +2,12 @@
 
 (define TAB-LENGTH 4)
 (define QUIT-TIMES 1)
+(define THEME "dark")
+
+;; PACKAGES
+
+;; First git clone it
+;; (add-package "smart_delimiters")
 
 ;; FUNCTIONS
 
@@ -13,22 +19,74 @@
   )
 
 
-;; KEY MAPPING
+(define (char-between ch lo hi)
+  (if (char>=? ch lo)
+      (char<=? ch hi)
+      #f))
 
-(map-key "CTRL-q" editor-quit)
-(map-key "CTRL-s" editor-save)
-(map-key "ARROW-UP" '(move-cursor "up"))
-(map-key "ARROW-DOWN" '(move-cursor "down"))
-(map-key "ARROW-RIGHT" '(move-cursor "right"))
-(map-key "ARROW-LEFT" '(move-cursor "left"))
-(map-key "ENTER" editor-insert-new-line)
-(map-key "CTRL-a" move-cursor-beg-line)
-(map-key "CTRL-e" move-cursor-end-line)
-(map-key "BACKSPACE" editor-delete-previous-char)
-(map-key "DEL" editor-delete-next-char)
-(map-key "PAGE-UP" move-cursor-page-up)
-(map-key "PAGE-DOWN" move-cursor-page-down)
-(map-key "CTRL-o" editor-open-file)
+(define (alphanumericp ch)
+  (if ch
+      (if (char-between ch #\a #\z)
+          #t
+          (if (char-between ch #\A #\Z)
+              #t
+              (if (char-between ch #\0 #\9)
+                  #t
+                  #f)))
+      #f))
+
+
+(define (word-char-p ch)
+  (if (alphanumericp ch)
+      #t
+      #f))
+
+(define editor-move-to-end-of-word (lambda () (
+  (if (word-char-p (editor-read-char))
+	((move-cursor "right")
+	(editor-move-to-end-of-word))
+    ))
+                                     ))
+
+(define enter-and-tab
+  (lambda ()
+    (editor-insert-new-line)
+    (let ((is-in (move-cursor "up")))
+      (do ((ch (editor-read-char) (editor-read-char)))
+          ((and (not (char=? ch #\space)) is-in) #f)
+        (move-cursor "down")
+        (editor-insert-char " ")
+        (set! is-in (move-cursor "up")))
+      (move-cursor "down"))))
+
+(add-prefix "user")
 
 
 
+(map-key "CTRL-x" '(editor-set-prefix "user") "no-prefix")
+(map-key "CTRL-g" '(editor-set-prefix "no-prefix") "user")
+(map-key "CTRL-c" editor-quit "user")
+(map-key "CTRL-s" editor-save "user")
+(map-key "ARROW-UP" '(move-cursor "up") "no-prefix")
+(map-key "ARROW-DOWN" '(move-cursor "down") "no-prefix")
+(map-key "ARROW-RIGHT" '(move-cursor "right") "no-prefix")
+(map-key "ARROW-LEFT" '(move-cursor "left") "no-prefix")
+(map-key "ENTER" enter-and-tab "no-prefix")
+(map-key "CTRL-a" move-cursor-beg-line "no-prefix")
+(map-key "CTRL-e" move-cursor-end-line "no-prefix")
+(map-key "BACKSPACE" editor-delete-previous-char "no-prefix")
+(map-key "DEL" editor-delete-next-char "no-prefix")
+(map-key "PAGE-UP" move-cursor-page-up "no-prefix")
+(map-key "PAGE-DOWN" move-cursor-page-down "no-prefix")
+(map-key "f" editor-open-file "user")
+(map-key "TAB" editor-insert-tab "no-prefix")
+(map-key "CTRL-s" buffer-find "no-prefix")
+(map-key "CTRL-r" buffer-find-reverse "no-prefix")
+(map-key "ARROW-RIGHT" editor-switch-next-buffer "user")
+(map-key "\"" editor-split-screen-vertical "user")
+(map-key "o" editor-switch-next-pane "user")
+(map-key "*" editor-unify-panes "user")
+(map-key "CTRL-y" editor-paste "no-prefix")
+(map-key "CTRL-k" editor-cut-end-line "no-prefix")
+(map-key "a" editor-move-cursor-beg-buffer "user")
+(map-key "z" editor-move-cursor-end-buffer "user")

include/buffer.h

@@ -0,0 +1,69 @@
+/**
+ * @file buffer.h
+ * @brief Buffer management for handling multiple open files
+ */
+
+#ifndef BUFFER_H_
+#define BUFFER_H_
+
+#include "data.h"
+
+/**
+ * @brief Creates a new buffer for a file
+ * @param filename Path to the file
+ * @return Buffer ID on success, -1 on failure
+ */
+int bufferCreate(const char *filename, enum bufferStatus_e state);
+
+/**
+ * @brief Switches to a specific buffer by ID
+ * @param buffer_id The buffer ID to switch to
+ * @return 0 on success, -1 on failure
+ */
+int bufferSwitch(int buffer_id);
+
+struct buffer_t *bufferFindById(int buffer_id);
+
+/**
+ * @brief Closes a buffer by ID
+ * @param buffer_id The buffer ID to close
+ * @return 0 on success, -1 on failure
+ */
+int bufferClose(int buffer_id);
+
+/**
+ * @brief Gets the current active buffer
+ * @return Pointer to current buffer_t, NULL if none
+ */
+struct buffer_t *bufferGetCurrent(void);
+
+/**
+ * @brief Lists all open buffers
+ * @return Number of open buffers
+ */
+int bufferListAll(void);
+
+/**
+ * @brief Saves current buffer to disk
+ * @return 0 on success, -1 on failure
+ */
+int bufferSave(void);
+
+/**
+ * @brief Saves all buffers to disk
+ * @return 0 on success, -1 on failure
+ */
+int bufferSaveAll(void);
+
+void bufferFind(struct buffer_t *buf);
+void bufferFindReverse(struct buffer_t* buf);
+void bufferInsertNewLine();
+void bufferInsertBytes(const char *src, int n);
+void bufferDelBytes();
+void bufferRowInsertBytes(struct buffer_t *buffer, row_t *row, int at, const char *src, int n);
+void bufferRowDelByte(struct buffer_t *buffer, row_t *row, int at, int n);
+void bufferInsertRow(struct buffer_t *buffer, int at, char *s, size_t len);
+void bufferFreeRow(row_t *row);
+
+
+#endif

include/builtins.h

@@ -3,30 +3,58 @@
 
 #include "lisp.h"
 
+// Mouvement
+
 Lisp moveCursor(Lisp args, LispError *e, LispContext ctx);
-
-Lisp mapKey(Lisp args, LispError *e, LispContext ctx);
-
-void registerBuiltin(char * key_sequence, LispCFunc f);
-
-Lisp editorQuit(Lisp args, LispError *e, LispContext ctx);
-
-Lisp l_editorSave(Lisp args, LispError *e, LispContext ctx);
-
-Lisp l_editorInsertNewLine(Lisp args, LispError* e, LispContext ctx);
-
 Lisp moveCursorBeginLine(Lisp args, LispError *e, LispContext ctx);
-
 Lisp moveCursorEndLine(Lisp args, LispError *e, LispContext ctx);
-
-Lisp deletePreviousChar(Lisp args, LispError *e, LispContext ctx);
-
 Lisp editorMoveCursorPageUp(Lisp args, LispError* e, LispContext ctx);
-
 Lisp editorMoveCursorPageDown(Lisp args, LispError *e, LispContext ctx);
 
-Lisp editorOpenFile(Lisp args, LispError *e, LispContext ctx);
+// Text editing
 
+Lisp l_editorInsertNewLine(Lisp args, LispError* e, LispContext ctx);
+Lisp l_editorInserTab(Lisp args, LispError *e, LispContext ctx);
+Lisp deletePreviousChar(Lisp args, LispError *e, LispContext ctx);
 Lisp editorPrintC(Lisp args, LispError *e, LispContext ctx);
+Lisp editorReadChar_L(Lisp args, LispError *e, LispContext ctx);
+
+// Editor
+
+Lisp editorQuit(Lisp args, LispError *e, LispContext ctx);
+Lisp l_editorSave(Lisp args, LispError *e, LispContext ctx);
+Lisp editorSetPrefix(Lisp args, LispError *e, LispContext ctx);
+Lisp editorPrefix(Lisp args, LispError *e, LispContext ctx);
+Lisp mapKey(Lisp args, LispError *e, LispContext ctx);
+void registerBuiltin(char * key_sequence, LispCFunc f);
+Lisp editorOpenFile(Lisp args, LispError *e, LispContext ctx);
+Lisp addPackage(Lisp args, LispError *e, LispContext ctx);
+
+
+// Buffer
+
+Lisp editorSwitchNextBuffer(Lisp args, LispError *e, LispContext ctx);
+Lisp bufferFind_L(Lisp args, LispError *e, LispContext ctx);
+Lisp bufferFindReverse_L(Lisp args, LispError *e, LispContext ctx);
+
+
+// Pane
+
+Lisp l_editorSplitScreenVertical(Lisp args, LispError *e, LispContext ctx);
+Lisp editorSwitchNextPane(Lisp args, LispError *e, LispContext ctx);
+Lisp editorUnifiedPanes(Lisp args, LispError *e, LispContext ctx);
+
+
+Lisp editorPaste(Lisp args, LispError *e, LispContext ctx);
+Lisp editorCutEndLine(Lisp args, LispError *e, LispContext ctx);
+
+Lisp editorMoveBegBuffer(Lisp args, LispError *e, LispContext ctx);
+Lisp editorMoveEndBuffer(Lisp args, LispError *e, LispContext ctx);
+
+// Other
+
+
+
+void free_structs(void);
 
 #endif

include/color.h

@@ -0,0 +1,123 @@
+#ifndef COLOR_H_
+#define COLOR_H_
+
+
+// ============================================================================
+// TEXT STYLES / ATTRIBUTES
+// ============================================================================
+#define ANSI_RESET          "\x1b[0m"      // Reset all attributes
+#define ANSI_BOLD           "\x1b[1m"      // Bold text
+#define ANSI_DIM            "\x1b[2m"      // Dim/faint text
+#define ANSI_ITALIC         "\x1b[3m"      // Italic text
+#define ANSI_UNDERLINE      "\x1b[4m"      // Underline text
+#define ANSI_BLINK          "\x1b[5m"      // Blinking text
+#define ANSI_REVERSE        "\x1b[7m"      // Reverse video (invert colors)
+#define ANSI_HIDDEN         "\x1b[8m"      // Hidden/invisible text
+#define ANSI_STRIKETHROUGH  "\x1b[9m"      // Strikethrough text
+
+// ============================================================================
+// FOREGROUND COLORS (30-37 standard, 90-97 bright)
+// ============================================================================
+#define ANSI_BLACK          "\x1b[30m"
+#define ANSI_RED            "\x1b[31m"
+#define ANSI_GREEN          "\x1b[32m"
+#define ANSI_YELLOW         "\x1b[33m"
+#define ANSI_BLUE           "\x1b[34m"
+#define ANSI_MAGENTA        "\x1b[35m"
+#define ANSI_CYAN           "\x1b[36m"
+#define ANSI_WHITE          "\x1b[37m"
+
+// Bright/Light foreground colors (90-97)
+#define ANSI_BRIGHT_BLACK   "\x1b[90m"
+#define ANSI_BRIGHT_RED     "\x1b[91m"
+#define ANSI_BRIGHT_GREEN   "\x1b[92m"
+#define ANSI_BRIGHT_YELLOW  "\x1b[93m"
+#define ANSI_BRIGHT_BLUE    "\x1b[94m"
+#define ANSI_BRIGHT_MAGENTA "\x1b[95m"
+#define ANSI_BRIGHT_CYAN    "\x1b[96m"
+#define ANSI_BRIGHT_WHITE   "\x1b[97m"
+
+// ============================================================================
+// BACKGROUND COLORS (40-47 standard, 100-107 bright)
+// ============================================================================
+#define ANSI_BG_BLACK       "\x1b[40m"
+#define ANSI_BG_RED         "\x1b[41m"
+#define ANSI_BG_GREEN       "\x1b[42m"
+#define ANSI_BG_YELLOW      "\x1b[43m"
+#define ANSI_BG_BLUE        "\x1b[44m"
+#define ANSI_BG_MAGENTA     "\x1b[45m"
+#define ANSI_BG_CYAN        "\x1b[46m"
+#define ANSI_BG_WHITE       "\x1b[47m"
+
+// Bright/Light background colors (100-107)
+#define ANSI_BG_BRIGHT_BLACK   "\x1b[100m"
+#define ANSI_BG_BRIGHT_RED     "\x1b[101m"
+#define ANSI_BG_BRIGHT_GREEN   "\x1b[102m"
+#define ANSI_BG_BRIGHT_YELLOW  "\x1b[103m"
+#define ANSI_BG_BRIGHT_BLUE    "\x1b[104m"
+#define ANSI_BG_BRIGHT_MAGENTA "\x1b[105m"
+#define ANSI_BG_BRIGHT_CYAN    "\x1b[106m"
+#define ANSI_BG_BRIGHT_WHITE   "\x1b[107m"
+
+// ============================================================================
+// 256-COLOR MODE (for more colors)
+// ============================================================================
+// Foreground: \x1b[38;5;Nm  where N is 0-255
+// Background: \x1b[48;5;Nm  where N is 0-255
+// Example macros:
+#define ANSI_FG_256(N)      "\x1b[38;5;" #N "m"
+#define ANSI_BG_256(N)      "\x1b[48;5;" #N "m"
+
+// ============================================================================
+// TRUE COLOR / 24-BIT COLOR (RGB)
+// ============================================================================
+// Foreground: \x1b[38;2;R;G;Bm
+// Background: \x1b[48;2;R;G;Bm
+// Example macros:
+#define ANSI_FG_RGB(R,G,B)  "\x1b[38;2;" #R ";" #G ";" #B "m"
+#define ANSI_BG_RGB(R,G,B)  "\x1b[48;2;" #R ";" #G ";" #B "m"
+
+// ============================================================================
+// CURSOR MOVEMENT
+// ============================================================================
+#define ANSI_CURSOR_UP(N)       "\x1b[" #N "A"    // Move up N lines
+#define ANSI_CURSOR_DOWN(N)     "\x1b[" #N "B"    // Move down N lines
+#define ANSI_CURSOR_RIGHT(N)    "\x1b[" #N "C"    // Move right N columns
+#define ANSI_CURSOR_LEFT(N)     "\x1b[" #N "D"    // Move left N columns
+#define ANSI_CURSOR_HOME        "\x1b[H"          // Move to home (0,0)
+#define ANSI_CURSOR_HIDE        "\x1b[?25l"       // Hide cursor
+#define ANSI_CURSOR_SHOW        "\x1b[?25h"       // Show cursor
+
+// ============================================================================
+// SCREEN CONTROL
+// ============================================================================
+#define ANSI_CLEAR_SCREEN   "\x1b[2J"      // Clear entire screen
+#define ANSI_CLEAR_LINE     "\x1b[K"       // Clear from cursor to end of line
+#define ANSI_CLEAR_UP       "\x1b[1J"      // Clear from cursor to start
+#define ANSI_CLEAR_DOWN     "\x1b[0J"      // Clear from cursor to end
+
+// ============================================================================
+// EXAMPLE USAGE
+// ============================================================================
+/*
+#include <stdio.h>
+
+int main(void) {
+    // Simple color example
+    printf("%sHello in Red%s\n", ANSI_RED, ANSI_RESET);
+    
+    // Bold and colored
+    printf("%s%sBold Green%s\n", ANSI_BOLD, ANSI_GREEN, ANSI_RESET);
+    
+    // Background color
+    printf("%s%sYellow on Blue%s\n", ANSI_YELLOW, ANSI_BG_BLUE, ANSI_RESET);
+    
+    // Combine multiple styles
+    printf("%s%s%sUnderlined Bold Cyan%s\n", 
+           ANSI_UNDERLINE, ANSI_BOLD, ANSI_CYAN, ANSI_RESET);
+    
+    return 0;
+}
+*/
+
+#endif

include/data.h

@@ -8,33 +8,103 @@
 #include "lisp.h"
 
 /**
- * \struct erow
+ * \struct row_t
  * \brief Store one editor row
  * \param
  * */
 
-typedef struct erow {
+typedef struct row {
   int size;     /**< Size of the line */
-  int rsize;    /**< Size of the render line */
+  int cap;    /**< Size of the render line */
   char *chars;  /**< Characters of the line */
-  char *render; /**< The actual line we will print */
-} erow;
+} row_t;
 
-enum editorStatus_e {
+typedef struct context_buffer_t
+{
+  int editor_x, editor_y;
+  int width, height;
+  row_t *rows;
+} ContextBuffer;
+
+/**
+ * @brief Split modes for screen layout
+ */
+typedef enum {
+    SPLIT_NONE = 0,      // Single buffer fullscreen
+    SPLIT_VERTICAL,      // Left-right split
+    SPLIT_HORIZONTAL     // Top-bottom split
+} SplitMode;
+
+/**
+ * @brief Represents an editor viewport/pane
+ */
+typedef struct {
+    int buffer_id;        // Which buffer this pane displays
+    int height;           // Height of this pane
+    int width;            // Width of this pane
+    int origin_x, origin_y;
+    int cursor_x;         // Local cursor x in this pane
+    int cursor_y;         // Local cursor y in this pane
+    int x_offset, y_offset;
+    int is_active;        // Is this pane currently active
+} EditorPane;
+
+/**
+ * @brief Screen layout manager
+ */
+typedef struct {
+    SplitMode mode;
+    EditorPane *panes;
+    int num_panes;
+    int active_pane;      // Index of active pane
+} ScreenLayout;
+
+
+typedef struct theme {
+  char *BACKGROUND_COLOR;
+  char *COLOR_KEYWORD;
+  char *COLOR_TYPE;
+  char *COLOR_STRING;
+  char *COLOR_COMMENT;
+  char *COLOR_NUMBER;
+  char *COLOR_DEFAULT;
+
+} theme_t;
+
+enum bufferStatus_e {
   IDLE,
   READ_ONLY,
-  READ_AND_WRITE, 
+  READ_AND_WRITE,
 };
 
 struct const_t {
   int TAB_LENGTH;
   int QUIT_TIMES;
+  char *THEME;
+};
+
+struct prefix_t {
+  char prefix_name[64];
+  int prefix_id;
 };
 
 struct keyBind_t {
   char *key_sequence;
+  int prefix_id;
   Lisp command;
-  
+};
+
+enum buffer_type { FILE_BUFF, TERMINAL_BUFF };
+
+struct buffer_t {
+  enum buffer_type type;
+  int buffer_id;
+  int x, y; /**< Position in the file */
+  row_t *row;
+  int numrows;
+  char *filename;
+  enum bufferStatus_e state;
+  int dirty;             /**< Has this buffer been modified since last save */
 };
 
 /**
@@ -43,32 +113,42 @@ struct keyBind_t {
  */
 struct editorConfig {
   int cursor_x, cursor_y; /**< Cursor position */
-  int rx;                 /**< Position in the render*/
-  int row_offset;         /**< Position scroll of lines */
-  int col_offset;         /**< Position scroll of colomns*/
   int screenrows;         /**< Terminal height*/
   int screencols;         /**< Terminal width*/
-  int numrows;            /**< Number of rows contained */
-  erow *row;              /**< Store all the rows printed */
+
+  ScreenLayout layout;
+
+  row_t *rows;        /**< Store all the rows printed */
+
+  ContextBuffer* context_buffers;
+
   int dirty;
-  char *filename;
-  enum editorStatus_e state;
-  char status_msg[80];
+
+  char *status_msg;
   time_t status_msg_time;
   struct termios orig_termios; /**< Terminal communication interface */
 
   struct const_t constantes;
   int quit_times_buffer;
 
+  char *init_file_path;
   FILE *fd_init_file;
   Lisp env;
   LispContext ctx;     /** Lisp context */
   Lisp ctx_data;       /** Lisp data context */
   LispError ctx_error; /** Lisp ctx error */
 
-  struct keyBind_t* key_binds;
+  struct keyBind_t *key_binds;
   int number_of_keybinds;
 
+  struct prefix_t *prefix;
+  int number_of_prefix;
+  int prefix_state;
+
+  struct buffer_t buffers[64];
+  int number_of_buffer;
+
+  theme_t theme;
 };
 
 /**

include/define.h

@@ -2,28 +2,41 @@
 #define DEFINE_H_
 
 #define CTRL_KEY(k) ((k) & 0x1f)
+#define ALT(k) ((k) | 0x200)  // set bit 9 to mark as Option combo
+
 
 #define ESCAPE '\x1b'
 #define CURSOR_TOP_LEFT "\x1b[H"
 #define HIDE_CURSOR "\x1b[?25l"
 #define SHOW_CURSOR "\x1b[?25h"
 #define ERASE_END_LINE "\x1b[K"
+#define TAB "\t"
+#define SPACE "\x20"
+#define APP_DEBUG
 
-enum editorKey {
-  BACKSPACE = 127,
-  ARROW_LEFT = 1000,
-  ARROW_RIGHT,
-  ARROW_UP,
-  ARROW_DOWN,
-  DEL_KEY,
-  BEG_LINE,
-  END_LINE,
-  PAGE_UP,
-  PAGE_DOWN,
-};
+enum editorKey_e {
+    BACKSPACE = 127,
+    ARROW_LEFT = 1000,
+    ARROW_RIGHT,
+    ARROW_UP,
+    ARROW_DOWN,
+    DEL_KEY,
+    BEG_LINE,
+    END_LINE,
+    PAGE_UP,
+    PAGE_DOWN,
+  };
 
 #define ABUF_INIT {NULL, 0}
 
-#define BELUGA_VERSION "1.1"
+#define BELUGA_VERSION "2.4"
+
+#ifdef __APPLE__
+#define CLIPBOARD_COPY_CMD  "pbcopy"
+#define CLIPBOARD_PASTE_CMD "pbpaste"
+#else
+#define CLIPBOARD_COPY_CMD  "xclip -selection clipboard"
+#define CLIPBOARD_PASTE_CMD "xclip -selection clipboard -o"
+#endif
 
 #endif // DEFINE_H_

include/editor_op.h

@@ -2,10 +2,12 @@
 #define EDITOR_OP_H_
 
 #include "data.h"
-void editorInsertChar(int c);
 
-void editorInsertNewLine();
+void editorSetStatusMessage(const char *fmt, ...);
+int editorRowCharCount(row_t *row, int x);
+int editorRowCxToByte(const row_t *row, int cursor_x);
+char *editorGetClipboard(void);
+void editorSetClipboard(const char *text, int len);
 
-void editorDelChar();
 
 #endif // EDITOR_OP_H_

include/file_io.h

@@ -2,18 +2,13 @@
 #define FILE_IO_H_
 
 #include "data.h"
-#include "row_op.h"
-#include "terminal.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/types.h>
 
-char *editorRowsToString(int *buffer_len);
-
-
 void editorCloseFile(void);
 
-void editorOpen(char *filename);
+void editorOpen(struct buffer_t *buffer);
 
 void editorSave();
 

include/input.h

@@ -20,11 +20,11 @@
 // END \x1b[4~ || <esc>[8~ || <esc>[F  || <esc>OF
 // DELETE \x1b[3~
 
-char *editorPrompt(char *prompt);
+char *editorPrompt(char *prompt, char * PlaceHolder, char bPathMode);
 
-char *key_to_string(int key);
+const char *fileCompletion(const char *path);
 
-void editorMoveCursor(int key);
+int editorMoveCursor(int key);
 
 int executeKeyBind(char *key_sequence);
 

include/lisp.h

@@ -1861,8 +1861,8 @@ static Lisp parse_symbol_(Lexer* lex, LispContext ctx)
     char scratch[LISP_IDENTIFIER_MAX];
     size_t length = lexer_copy_token(lex, 0, LISP_IDENTIFIER_MAX, scratch);
     // always convert symbols to uppercase
-    for (int i = 0; i < length; ++i)
-        scratch[i] = toupper(scratch[i]);
+    //   for (int i = 0; i < length; ++i)
+    //    scratch[i] = toupper(scratch[i]);
     return symbol_intern_(ctx.p->symbols, scratch, length, ctx);
 }
 
@@ -2075,8 +2075,10 @@ static Lisp parse(Lexer* lex, LispError* out_error, LispContext ctx)
         result = lisp_cons(get_sym(SYM_BEGIN, ctx), lisp_list_reverse(result), ctx);
     }
 
-    if (out_error) *out_error = error;
+    if (out_error)
+      *out_error = error;
     return result;
+
 }
 
 Lisp lisp_read(const char *program, LispError* out_error, LispContext ctx)
@@ -2122,6 +2124,7 @@ void* fread_all_(FILE* file, size_t* out_size) {
                 return NULL;
             }
             data = new_data;
+            memset(data + *out_size, 0, cap - *out_size);
         }
 
         size_t read = fread(data + *out_size, 1, BLOCK_SIZE, file);
@@ -3183,17 +3186,17 @@ LispContext lisp_init(void)
     ctx.p->macros = lisp_make_table(ctx);
 
     Lisp* c = ctx.p->symbol_cache;
-    c[SYM_IF] = lisp_make_symbol("IF", ctx);
-    c[SYM_BEGIN] = lisp_make_symbol("BEGIN", ctx);
-    c[SYM_QUOTE] = lisp_make_symbol("QUOTE", ctx);
-    c[SYM_QUASI_QUOTE] = lisp_make_symbol("QUASIQUOTE", ctx);
-    c[SYM_UNQUOTE] = lisp_make_symbol("UNQUOTE", ctx);
-    c[SYM_UNQUOTE_SPLICE] = lisp_make_symbol("UNQUOTESPLICE", ctx);
-    c[SYM_DEFINE] = lisp_make_symbol("_DEF", ctx);
-    c[SYM_DEFINE_MACRO] = lisp_make_symbol("DEFINE-MACRO", ctx);
-    c[SYM_SET] = lisp_make_symbol("_SET!", ctx);
+    c[SYM_IF] = lisp_make_symbol("if", ctx);
+    c[SYM_BEGIN] = lisp_make_symbol("begin", ctx);
+    c[SYM_QUOTE] = lisp_make_symbol("quote", ctx);
+    c[SYM_QUASI_QUOTE] = lisp_make_symbol("quasiquote", ctx);
+    c[SYM_UNQUOTE] = lisp_make_symbol("unquote", ctx);
+    c[SYM_UNQUOTE_SPLICE] = lisp_make_symbol("unquotesplice", ctx);
+    c[SYM_DEFINE] = lisp_make_symbol("_def", ctx);
+    c[SYM_DEFINE_MACRO] = lisp_make_symbol("define-macro", ctx);
+    c[SYM_SET] = lisp_make_symbol("_set!", ctx);
     c[SYM_LAMBDA] = lisp_make_symbol("/\\_", ctx);
-    c[SYM_CONS] = lisp_make_symbol("CONS", ctx);
+    c[SYM_CONS] = lisp_make_symbol("cons", ctx);
     return ctx;
 }
 

include/lisp_lib.h

@@ -36,7 +36,7 @@ static const char* lib_0_sequences_src_ =
            (if (pair? args) \n\
                (if (pair? (cdr args)) \n\
                    (if (pair? (cdr (cdr args))) \n\
-                       `(/\\_ ,(car args) ,(cons 'BEGIN (cdr args))) \n\
+                       `(/\\_ ,(car args) ,(cons 'begin (cdr args))) \n\
                        `(/\\_ ,(car args) ,(car (cdr args)))) \n\
                    (syntax-error \"lambda missing body expressions: (lambda (args) body)\")) \n\
                (syntax-error \"lambda missing argument: (lambda (args) body)\")))) \n\
@@ -44,18 +44,18 @@ static const char* lib_0_sequences_src_ =
 (define-macro set! (lambda (var x) \n\
                      (begin \n\
                        (if (not (symbol? var)) (syntax-error \"set! not a variable\")) \n\
-                       `(_SET! ,var ,x)))) \n\
+                       `(_set! ,var ,x)))) \n\
  \n\
 (define-macro define \n\
               (lambda (var . exprs) \n\
                 (if (symbol? var) \n\
                     (if (pair? (cdr exprs)) \n\
                         (syntax-error \"define: (define var x)\") \n\
-                        `(_DEF ,var ,(car exprs))) \n\
+                        `(_def ,var ,(car exprs))) \n\
                     (if (pair? var) \n\
-                        `(_DEF ,(car var) \n\
-                               (LAMBDA ,(cdr var) \n\
-                                       ,(if (null? (cdr exprs)) (car exprs) (cons 'BEGIN exprs)))) \n\
+                        `(_def ,(car var) \n\
+                               (lambda ,(cdr var) \n\
+                                       ,(if (null? (cdr exprs)) (car exprs) (cons 'begin exprs)))) \n\
                         (syntax-error \"define: not a symbol\") )))) \n\
   \n\
 (define (first x) (car x))  \n\
@@ -98,13 +98,13 @@ static const char* lib_0_sequences_src_ =
 (define (_expand-shorthand-body path)  \n\
   (if (null? path) (cons 'pair '())  \n\
       (list (if (char=? (car path) #\\A)  \n\
-            (cons 'CAR (_expand-shorthand-body (cdr path)))))))  \n\
+            (cons 'car (_expand-shorthand-body (cdr path)))))))  \n\
  \n\
 (define (_expand-shorthand text)  \n\
-  (cons 'DEFINE  (cons (list (string->symbol (string-append \"C\" text \"R\")) 'pair)  \n\
+  (cons 'define  (cons (list (string->symbol (string-append \"C\" text \"R\")) 'pair)  \n\
         (_expand-shorthand-body (string->list text)))))  \n\
  \n\
-(define-macro _shorthand-accessors (lambda args (cons 'BEGIN (map1 _expand-shorthand args))))  \n\
+(define-macro _shorthand-accessors (lambda args (cons 'begin (map1 _expand-shorthand args))))  \n\
  \n\
 (define (vector . args) (list->vector args)) \n\
  \n\
@@ -124,14 +124,14 @@ static const char* lib_0_sequences_src_ =
 
 static const char* lib_1_forms_src_ = 
 "(define (_make-lambda args body)  \n\
-  (list 'LAMBDA args (if (null? (cdr body)) (car body) (cons 'BEGIN body))))  \n\
+  (list 'lambda args (if (null? (cdr body)) (car body) (cons 'begin body))))  \n\
   \n\
  \n\
-; (LET <name> ((<var0> <expr0>) ... (<varN> <expr1>)) <body0> ... <bodyN>) \n\
-;  => ((LAMBDA (<var0> ... <varN>) (BEGIN <body0> ... <bodyN>)) <expr0> ... <expr1>)             \n\
+; (let <name> ((<var0> <expr0>) ... (<varN> <expr1>)) <body0> ... <bodyN>) \n\
+;  => ((lambda (<var0> ... <varN>) (begin <body0> ... <bodyN>)) <expr0> ... <expr1>)             \n\
 ;  => named  \n\
 ;    ((lambda () \n\
-;        (define <name> (LAMBDA (<var0> ... <varN>) (BEGIN <body0> ... <bodyN>))) \n\
+;        (define <name> (lambda (<var0> ... <varN>) (begin <body0> ... <bodyN>))) \n\
 ;        (<name> <expr0> ... <exprN>))) \n\
  \n\
 (define (_check-binding-list bindings)  \n\
@@ -145,7 +145,7 @@ static const char* lib_1_forms_src_ =
   (define initial-args (map1 (lambda (entry) (second entry)) bindings))  \n\
   (if (null? var)  \n\
       (cons body-func initial-args)  \n\
-      (list (_make-lambda '() (list (list 'DEFINE var body-func) (cons var initial-args))))))  \n\
+      (list (_make-lambda '() (list (list 'define var body-func) (cons var initial-args))))))  \n\
  \n\
 (define-macro let (lambda args   \n\
                     (if (pair? (first args))  \n\
@@ -153,8 +153,8 @@ static const char* lib_1_forms_src_ =
                         (_let->combination (first args) (second args) (cdr (cdr args))))))  \n\
  \n\
 (define (_let*-helper bindings body)  \n\
-  (if (null? bindings) (if (null? (cdr body)) (car body) (cons 'BEGIN body))  \n\
-      (list 'LET (list (car bindings)) (_let*-helper (cdr bindings) body))))  \n\
+  (if (null? bindings) (if (null? (cdr body)) (car body) (cons 'begin body))  \n\
+      (list 'let (list (car bindings)) (_let*-helper (cdr bindings) body))))  \n\
  \n\
 (define-macro let* (lambda (bindings . body)  \n\
                      (_check-binding-list bindings)  \n\
@@ -163,17 +163,17 @@ static const char* lib_1_forms_src_ =
 (define-macro letrec (lambda (bindings . body)  \n\
                        (_check-binding-list bindings)  \n\
                        (cons (_make-lambda (map1 (lambda (entry) (first entry)) bindings)  \n\
-                                           (append (map1 (lambda (entry) (list 'SET! (first entry) (second entry)))  \n\
+                                           (append (map1 (lambda (entry) (list 'set! (first entry) (second entry)))  \n\
                                                          bindings) body))  \n\
                              (map1 (lambda (entry) '()) bindings))))  \n\
  \n\
  \n\
-; (COND (<pred0> <expr0>) \n\
+; (cond (<pred0> <expr0>) \n\
 ;       (<pred1> <expr1>) \n\
 ;        ... \n\
 ;        (else <expr-1>))  \n\
 ; => \n\
-; (IF <pred0> <expr0> \n\
+; (if <pred0> <expr0> \n\
 ;      (if <pred1> <expr1> \n\
 ;          .... \n\
 ;      (if <predN> <exprN> <expr-1>)) ... ) \n\
@@ -187,11 +187,11 @@ static const char* lib_1_forms_src_ =
  \n\
 (define (_cond-helper clauses)  \n\
   (if (null? clauses) '()  \n\
-      (if (eq? (car (car clauses)) 'ELSE)  \n\
-          (cons 'BEGIN (cdr (car clauses)))  \n\
-          (list 'IF  \n\
+      (if (eq? (car (car clauses)) 'else)  \n\
+          (cons 'begin (cdr (car clauses)))  \n\
+          (list 'if  \n\
                 (car (car clauses))  \n\
-                (cons 'BEGIN (cdr (car clauses)))  \n\
+                (cons 'begin (cdr (car clauses)))  \n\
                 (_cond-helper (cdr clauses))))))  \n\
  \n\
 (define-macro cond (lambda clauses  \n\
@@ -206,26 +206,26 @@ static const char* lib_2_forms_src_ =
   (cond ((null? preds) #t)  \n\
         ((null? (cdr preds)) (car preds))  \n\
         (else  \n\
-          `(IF ,(car preds) ,(_and-helper (cdr preds)) #f))))  \n\
+          `(if ,(car preds) ,(_and-helper (cdr preds)) #f))))  \n\
 (define-macro and (lambda preds (_and-helper preds)))  \n\
  \n\
 (define (_or-helper preds var)  \n\
   (cond ((null? preds) #f)  \n\
         ((null? (cdr preds)) (car preds))  \n\
         (else  \n\
-          `(BEGIN (SET! ,var ,(car preds))  \n\
-                  (IF ,var ,var ,(_or-helper (cdr preds) var))))))  \n\
+          `(begin (set! ,var ,(car preds))  \n\
+                  (if ,var ,var ,(_or-helper (cdr preds) var))))))  \n\
  \n\
 (define-macro or (lambda preds  \n\
                    (let ((var (gensym)))  \n\
-                     `(LET ((,var '())) ,(_or-helper preds var)))))  \n\
+                     `(let ((,var '())) ,(_or-helper preds var)))))  \n\
  \n\
 (define-macro case (lambda (key . clauses)  \n\
                      (let ((expr (gensym)))  \n\
-                       `(LET ((,expr ,key))  \n\
-                          ,(cons 'COND (map1 (lambda (entry)  \n\
+                       `(let ((,expr ,key))  \n\
+                          ,(cons 'cond (map1 (lambda (entry)  \n\
                                                (cons (if (pair? (car entry))  \n\
-                                                         `(MEMV ,expr (quote ,(car entry)))  \n\
+                                                         `(memv ,expr (quote ,(car entry)))  \n\
                                                          (car entry))  \n\
                                                      (cdr entry))) clauses))))))  \n\
  \n\
@@ -234,23 +234,24 @@ static const char* lib_2_forms_src_ =
                 `(begin (set! ,l (cons ,v ,l)) ,l)))  \n\
  \n\
 ; (DO ((<var0> <init0> <step0>) ...)  (<test> <result>) <body>) \n\
-(define-macro do  \n\
-              (lambda (vars loop-check . loops)  \n\
-                (let ( (names '()) (inits '()) (steps '()) (f (gensym)) )  \n\
-                  (for-each1 (lambda (var)  \n\
-                               (push (car var) names)  \n\
-                               (set! var (cdr var))  \n\
-                               (push (car var) inits)  \n\
-                               (set! var (cdr var))  \n\
-                               (push (car var) steps)) vars)  \n\
-                  `((LAMBDA ()  \n\
-                      (DEFINE ,f (LAMBDA ,names  \n\
-                                   (IF ,(car loop-check)  \n\
-                                       ,(if (pair? (cdr loop-check)) (car (cdr loop-check)) '())  \n\
-                                       ,(cons 'BEGIN (append loops (list (cons f steps)))) )))  \n\
-                      ,(cons f inits)  \n\
-                      )) )))  \n\
  \n\
+(define-macro do   \n\
+  (lambda (vars loop-check . loops)   \n\
+    (let ( (names '()) (inits '()) (steps '()) (f (gensym)) )   \n\
+      (for-each1 (lambda (var-spec)   \n\
+                   (push (car var-spec) names) \n\
+                   (push (car (cdr var-spec)) inits) \n\
+                   (if (pair? (cdr (cdr var-spec))) \n\
+                       (push (car (cdr (cdr var-spec))) steps) \n\
+                       (push (car var-spec) steps))) vars)   \n\
+      `((lambda ()   \n\
+          (define ,f (lambda ,names   \n\
+                       (if ,(car loop-check)   \n\
+                           ,(if (pair? (cdr loop-check)) (car (cdr loop-check)) '())   \n\
+                           ,(cons 'begin (append loops (list (cons f steps)))) )))   \n\
+          ,(cons f inits)   \n\
+          )) ))) \n\
+\n\
 (define-macro dotimes  \n\
               (lambda (form body)  \n\
                 (apply (lambda (i n . result)  \n\
@@ -262,18 +263,18 @@ static const char* lib_2_forms_src_ =
 (define-macro swap! \n\
               (lambda (x y) \n\
                 (let ((temp (gensym))) \n\
-                  `(LET ((,temp ,x)) \n\
-                        (SET! ,temp ,x) \n\
-                        (SET! ,x ,y) \n\
-                        (SET! ,y ,temp))))) \n\
+                  `(let ((,temp ,x)) \n\
+                        (set! ,temp ,x) \n\
+                        (set! ,x ,y) \n\
+                        (set! ,y ,temp))))) \n\
  \n\
 (define-macro inc! ; CL incf \n\
               (lambda (x) \n\
-                `(SET! ,x (+ ,x 1)))) \n\
+                `(set! ,x (+ ,x 1)))) \n\
  \n\
 (define-macro dec! ; CL decf \n\
               (lambda (x) \n\
-                `(SET! ,x (- ,x 1))))";
+                `(set! ,x (- ,x 1))))";
 
 static const char* lib_3_math_src_ = 
 "(define (number? x) (real? x))  \n\
@@ -445,7 +446,7 @@ static const char* lib_4_sequences_src_ =
 
 static const char* lib_5_streams_src_ = 
 "(define-macro delay (lambda (expr) \n\
-                      `(make-promise ,(cons 'LAMBDA \n\
+                      `(make-promise ,(cons 'lambda \n\
                                             (cons '() \n\
                                                   (cons expr '())))))) \n\
  \n\
@@ -1926,182 +1927,178 @@ static Lisp sch_is_cont(Lisp args, LispError* e, LispContext ctx)
 
 static const LispFuncDef lib_cfunc_defs[] = {
     
-    { "ERROR", sch_error },
-    { "SYNTAX-ERROR", sch_syntax_error },
+    { "error", sch_error },
+    { "syntax-error", sch_syntax_error },
 
-    // Output Procedures https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Output-Procedures.html
-    { "_WRITE", sch_write },
-    { "_DISPLAY", sch_display },
-    { "_WRITE-CHAR", sch_write_char },
-    { "_FLUSH-OUTPUT-PORT", sch_flush },
-    { "_READ", sch_read },
-    { "INPUT-PORT?", sch_is_port_in },
-    { "OUTPUT-PORT?", sch_is_port_out },
-    { "OPEN-INPUT-FILE", sch_open_input },
-    { "OPEN-OUTPUT-FILE", sch_open_output },
-    { "CLOSE-INPUT-PORT", sch_port_close },
-    { "CLOSE-OUTPUT-PORT", sch_port_close },
-    { "EOF-OBJECT?", sch_is_eof },
+    // Output Procedures
+    { "_write", sch_write },
+    { "_display", sch_display },
+    { "_write-char", sch_write_char },
+    { "_flush-output-port", sch_flush },
+    { "_read", sch_read },
+    { "input-port?", sch_is_port_in },
+    { "output-port?", sch_is_port_out },
+    { "open-input-file", sch_open_input },
+    { "open-output-file", sch_open_output },
+    { "close-input-port", sch_port_close },
+    { "close-output-port", sch_port_close },
+    { "eof-object?", sch_is_eof },
     
-    // Universal Time https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Universal-Time.html
-    { "GET-UNIVERSAL-TIME", sch_univeral_time },
-    { "PRINT-GC-STATISTICS", sch_print_gc_stats },
+    // Universal Time
+    { "get-universal-time", sch_univeral_time },
+    { "print-gc-statistics", sch_print_gc_stats },
     
-    { "MACROEXPAND", sch_macroexpand },
+    { "macroexpand", sch_macroexpand },
     
-    // Equivalence Predicates https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Equivalence-Predicates.html
-    { "EQ?", sch_exact_eq },
-    { "EQV?", sch_equal },
-    { "EQUAL?", sch_equal_r },
+    // Equivalence Predicates
+    { "eq?", sch_exact_eq },
+    { "eqv?", sch_equal },
+    { "equal?", sch_equal_r },
     
-    // Booleans https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Booleans.html
-    { "BOOLEAN?", sch_is_boolean },
-    { "NOT", sch_not },
+    // Booleans
+    { "boolean?", sch_is_boolean },
+    { "not", sch_not },
 
     // PAIRS
-    { "CONS", sch_cons },
-    { "CAR", sch_car },
-    { "CDR", sch_cdr },
-    { "SET-CAR!", sch_set_car },
-    { "SET-CDR!", sch_set_cdr },
-    { "NULL?", sch_is_null },
-    { "PAIR?", sch_is_pair },
+    { "cons", sch_cons },
+    { "car", sch_car },
+    { "cdr", sch_cdr },
+    { "set-car!", sch_set_car },
+    { "set-cdr!", sch_set_cdr },
+    { "null?", sch_is_null },
+    { "pair?", sch_is_pair },
 
-    // Lists https://groups.csail.mit.edu/mac/ftpdir/scheme-7.4/doc-html/scheme_8.html
-    { "LIST", sch_list },
-    { "LIST?", sch_is_list },
-    { "MAKE-LIST", sch_make_list },
-    { "LIST-COPY", sch_list_copy },
-    { "LENGTH", sch_length },
-    { "APPEND", sch_append },
-    { "APPEND-REVERSE!", sch_append_reverse },
-    { "LIST-REF", sch_list_ref },
-    { "NTHCDR", sch_list_advance },
+    // Lists
+    { "list", sch_list },
+    { "list?", sch_is_list },
+    { "make-list", sch_make_list },
+    { "list-copy", sch_list_copy },
+    { "length", sch_length },
+    { "append", sch_append },
+    { "append-reverse!", sch_append_reverse },
+    { "list-ref", sch_list_ref },
+    { "nthcdr", sch_list_advance },
 
-    // Vectors https://groups.csail.mit.edu/mac/ftpdir/scheme-7.4/doc-html/scheme_9.html#SEC82
-    { "VECTOR?", sch_is_vector },
-    { "MAKE-VECTOR", sch_make_vector },
-    { "VECTOR-GROW", sch_vector_grow },
-    { "VECTOR-LENGTH", sch_vector_length },
-    { "VECTOR-SET!", sch_vector_set },
-    { "VECTOR-SWAP!", sch_vector_swap },
-    { "VECTOR-REF", sch_vector_ref },
-    { "VECTOR-FILL!", sch_vector_fill },
-    { "VECTOR-ASSQ", sch_vector_assq },
-    { "SUBVECTOR", sch_subvector },
-    { "LIST->VECTOR", sch_list_to_vector },
-    { "VECTOR->LIST", sch_vector_to_list },
+    // Vectors
+    { "vector?", sch_is_vector },
+    { "make-vector", sch_make_vector },
+    { "vector-grow", sch_vector_grow },
+    { "vector-length", sch_vector_length },
+    { "vector-set!", sch_vector_set },
+    { "vector-swap!", sch_vector_swap },
+    { "vector-ref", sch_vector_ref },
+    { "vector-fill!", sch_vector_fill },
+    { "vector-assq", sch_vector_assq },
+    { "subvector", sch_subvector },
+    { "list->vector", sch_list_to_vector },
+    { "vector->list", sch_vector_to_list },
 
-    // Strings https://groups.csail.mit.edu/mac/ftpdir/scheme-7.4/doc-html/scheme_7.html#SEC61
-    { "STRING?", sch_is_string },
-    { "MAKE-STRING", sch_make_string },
-    { "STRING=?", sch_equal_r },
-    { "STRING<?", sch_string_less },
-    { "SUBSTRING", sch_substring },
-    { "STRING-NULL?", sch_string_is_null },
-    { "STRING-LENGTH", sch_string_length },
-    { "STRING-REF", sch_string_ref },
-    { "STRING-SET!", sch_string_set },
-    { "STRING-UPCASE", sch_string_upcase },
-    { "STRING-DOWNCASE", sch_string_downcase },
-    { "STRING-APPEND", sch_string_append },
-    { "STRING->LIST", sch_string_to_list },
-    { "LIST->STRING", sch_list_to_string },
-    { "STRING->NUMBER", sch_string_to_number },
-    { "NUMBER->STRING", sch_number_to_string },
+    // Strings
+    { "string?", sch_is_string },
+    { "make-string", sch_make_string },
+    { "string=?", sch_equal_r },
+    { "string<?", sch_string_less },
+    { "substring", sch_substring },
+    { "string-null?", sch_string_is_null },
+    { "string-length", sch_string_length },
+    { "string-ref", sch_string_ref },
+    { "string-set!", sch_string_set },
+    { "string-upcase", sch_string_upcase },
+    { "string-downcase", sch_string_downcase },
+    { "string-append", sch_string_append },
+    { "string->list", sch_string_to_list },
+    { "list->string", sch_list_to_string },
+    { "string->number", sch_string_to_number },
+    { "number->string", sch_number_to_string },
 
-    // Characters https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Characters.html#Characters
-    { "CHAR?", sch_is_char },
-    { "CHAR=?", sch_equals },
-    { "CHAR<?", sch_char_less },
+    // Characters
+    { "char?", sch_is_char },
+    { "char=?", sch_equals },
+    { "char<?", sch_char_less },
 
-    { "CHAR-UPCASE", sch_char_upcase },
-    { "CHAR-DOWNCASE", sch_char_downcase },
-    { "CHAR-WHITESPACE?", sch_char_is_white },
-    { "CHAR-ALPHANUMERIC?", sch_char_is_alphanum },
-    { "CHAR-ALPHABETIC?", sch_char_is_alpha },
-    { "CHAR-NUMERIC?", sch_char_is_number },
-    { "CHAR->INTEGER", sch_char_to_int },
+    { "char-upcase", sch_char_upcase },
+    { "char-downcase", sch_char_downcase },
+    { "char-whitespace?", sch_char_is_white },
+    { "char-alphanumeric?", sch_char_is_alphanum },
+    { "char-alphabetic?", sch_char_is_alpha },
+    { "char-numeric?", sch_char_is_number },
+    { "char->integer", sch_char_to_int },
 
-    // Association Lists https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Association-Lists.html
-    // Numerical operations https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Numerical-operations.html
+    // Numerical operations
     { "=", sch_equals },
     { "+", sch_add },
     { "-", sch_sub },
     { "*", sch_mult },
     { "/", sch_divide },
     { "<", sch_less },
-    { "INTEGER?", sch_is_int },
-    { "EVEN?", sch_is_even },
-    { "REAL?", sch_is_real },
-    { "EXP", sch_exp },
-    { "EXPT", sch_power },
-    { "LOG", sch_log },
-    { "SIN", sch_sin },
-    { "COS", sch_cos },
-    { "TAN", sch_tan },
-    { "ATAN", sch_atan },
-    { "SQRT", sch_sqrt },
-    { "ROUND", sch_round },
-    { "FLOOR", sch_floor },
-    { "CEILING", sch_ceiling },
-    { "QUOTIENT", sch_quotient },
-    { "REMAINDER", sch_remainder },
-    { "MODULO", sch_modulo },
-    { "ABS", sch_abs },
-    { "MAGNITUDE", sch_abs },
-    { "EXACT?", sch_is_int },
-    { "EXACT->INEXACT", sch_to_inexact },
-    { "INEXACT->EXACT", sch_to_exact },
+    { "integer?", sch_is_int },
+    { "even?", sch_is_even },
+    { "real?", sch_is_real },
+    { "exp", sch_exp },
+    { "expt", sch_power },
+    { "log", sch_log },
+    { "sin", sch_sin },
+    { "cos", sch_cos },
+    { "tan", sch_tan },
+    { "atan", sch_atan },
+    { "sqrt", sch_sqrt },
+    { "round", sch_round },
+    { "floor", sch_floor },
+    { "ceiling", sch_ceiling },
+    { "quotient", sch_quotient },
+    { "remainder", sch_remainder },
+    { "modulo", sch_modulo },
+    { "abs", sch_abs },
+    { "magnitude", sch_abs },
+    { "exact?", sch_is_int },
+    { "exact->inexact", sch_to_inexact },
+    { "inexact->exact", sch_to_exact },
     
-    // Symbols https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Symbols.html
-    { "SYMBOL?", sch_is_symbol },
-    { "SYMBOL<?", sch_symbol_less },
-    { "STRING->SYMBOL", sch_string_to_symbol },
-    { "SYMBOL->STRING", sch_symbol_to_string },
-    { "GENERATE-UNINTERNED-SYMBOL", sch_gensym },
-    { "GENSYM", sch_gensym },
+    // Symbols
+    { "symbol?", sch_is_symbol },
+    { "symbol<?", sch_symbol_less },
+    { "string->symbol", sch_string_to_symbol },
+    { "symbol->string", sch_symbol_to_string },
+    { "generate-uninterned-symbol", sch_gensym },
+    { "gensym", sch_gensym },
 
-    // Environments https://groups.csail.mit.edu/mac/ftpdir/scheme-7.4/doc-html/scheme_14.html
-    { "EVAL", sch_eval },
-    { "SCHEME-REPORT-ENVIRONMENT", sch_system_env },
-    { "INTERACTION-ENVIRONMENT", sch_user_env },
-    // { "THE-ENVIRONMENT", sch_current_env },
+    // Environments
+    { "eval", sch_eval },
+    { "scheme-report-environment", sch_system_env },
+    { "interaction-environment", sch_user_env },
     
-    // Hash Tables https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Basic-Hash-Table-Operations.html#Basic-Hash-Table-Operations
-    { "HASH-TABLE?", sch_is_table },
-    { "MAKE-HASH-TABLE", sch_table_make },
-    { "HASH-TABLE-SET!", sch_table_set },
-    { "HASH-TABLE-REF", sch_table_get },
-    { "HASH-TABLE-SIZE", sch_table_size },
-    { "HASH-TABLE->ALIST", sch_table_to_alist },
+    // Hash Tables
+    { "hash-table?", sch_is_table },
+    { "make-hash-table", sch_table_make },
+    { "hash-table-set!", sch_table_set },
+    { "hash-table-ref", sch_table_get },
+    { "hash-table-size", sch_table_size },
+    { "hash-table->alist", sch_table_to_alist },
 
-    { "PROMISE?", sch_is_promise },
-    { "MAKE-PROMISE", sch_make_promise },
-    { "_PROMISE-PROCEDURE", sch_promise_proc },
-    { "_PROMISE-STORE!", sch_promise_store },
-    { "PROMISE-VALUE", sch_promise_val },
-    { "PROMISE-FORCED?", sch_promise_forced },
+    { "promise?", sch_is_promise },
+    { "make-promise", sch_make_promise },
+    { "_promise-procedure", sch_promise_proc },
+    { "_promise-store!", sch_promise_store },
+    { "promise-value", sch_promise_val },
+    { "promise-forced?", sch_promise_forced },
     
-    // Procedures https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Procedure-Operations.html#Procedure-Operations
-    { "APPLY", sch_apply },
-    { "COMPILED-PROCEDURE?", sch_is_func },
-    { "COMPOUND-PROCEDURE?", sch_is_lambda },
-    { "PROCEDURE-ENVIRONMENT", sch_lambda_env },
-    // TOOD: Almost standard
-    { "PROCEDURE-BODY", sch_lambda_body },
-    { "CALL/CC", sch_call_cc },
-    { "CONTINUATION?", sch_is_cont },
+    // Procedures
+    { "apply", sch_apply },
+    { "compiled-procedure?", sch_is_func },
+    { "compound-procedure?", sch_is_lambda },
+    { "procedure-environment", sch_lambda_env },
+    { "procedure-body", sch_lambda_body },
+    { "call/cc", sch_call_cc },
+    { "continuation?", sch_is_cont },
 
-    // Random Numbers https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Random-Numbers.html
-    { "RANDOM", sch_pseudo_rand },
-    { "RANDOM-SEED!", sch_pseudo_seed },
+    // Random Numbers
+    { "random", sch_pseudo_rand },
+    { "random-seed!", sch_pseudo_seed },
    
-    // Garbage Collection https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-user/Garbage-Collection.html
-    { "GC-FLIP", sch_gc_flip },
+    // Garbage Collection
+    { "gc-flip", sch_gc_flip },
     
     { NULL, NULL }
-    
 };
 
 void lisp_lib_load(LispContext ctx)
@@ -2111,14 +2108,14 @@ void lisp_lib_load(LispContext ctx)
 
     lisp_table_set(
             table,
-            lisp_make_symbol("_CURRENT-OUTPUT-PORT", ctx),
+            lisp_make_symbol("_current-output-port", ctx),
             lisp_make_port(stdout, 0),
             ctx
             );
 
     lisp_table_set(
             table,
-            lisp_make_symbol("_CURRENT-INPUT-PORT", ctx),
+            lisp_make_symbol("_current-input-port", ctx),
             lisp_make_port(stdin, 1),
             ctx
             );

include/output.h

@@ -1,11 +1,7 @@
 #ifndef OUTPUT_H_
 #define OUTPUT_H_
 
-#include "append_buffer.h"
 #include "data.h"
-#include "define.h"
-#include "row_op.h"
-#include <stdio.h>
 #include <unistd.h>
 
 /**
@@ -13,8 +9,6 @@
  * \brief Draws left rows of the editor.
  */
 
-void editorDrawRows(struct abuf *ab);
-
 void editorRefreshScreen();
 
 void editorScroll();
@@ -23,6 +17,4 @@ void editorDrawStatusBar(struct abuf *ab);
 
 void editorDrawMessageBar(struct abuf *ab);
 
-void editorSetStatusMessage(const char *fmt, ...);
-
 #endif // OUTPUT_H_

include/row_op.h

@@ -8,20 +8,8 @@
 #include <time.h>
 #include <unistd.h>
 
-int editorRowCxToRx(erow *row, int cursor_x);
 
-void editorUpdateRow(erow *row);
 
-void editorInsertRow(int at, char *s, size_t len);
 
-void editorFreeRow(erow *row);
-
-void editorDelRow(int at);
-
-void editorRowInsertChar(erow *row, int at, int c);
-
-void editorRowAppendString(erow *row, char *s, size_t len);
-
-void editorRowDelchar(erow *row, int at);
 
 #endif // ROW_OP_H_

include/split_screen.h

@@ -0,0 +1,62 @@
+/**
+ * @file split_screen.h
+ * @brief Split screen management for displaying multiple buffers
+ */
+
+#ifndef SPLIT_SCREEN_H_
+#define SPLIT_SCREEN_H_
+
+#include "data.h"
+
+/**
+ * @brief Initializes split screen system
+ */
+void splitScreenInit(void);
+
+/**
+ * @brief Splits screen vertically (left-right)
+ * @param buffer_id_left Buffer ID for left pane
+ * @param buffer_id_right Buffer ID for right pane
+ * @return 0 on success, -1 on failure
+ */
+int splitScreenVertical(int buffer_id_left, int buffer_id_right);
+
+/**
+ * @brief Splits screen horizontally (top-bottom)
+ * @param buffer_id_top Buffer ID for top pane
+ * @param buffer_id_bottom Buffer ID for bottom pane
+ * @return 0 on success, -1 on failure
+ */
+int splitScreenHorizontal(int buffer_id_top, int buffer_id_bottom);
+
+/**
+ * @brief Returns to single buffer fullscreen
+ */
+void splitScreenUnify(void);
+
+/**
+ * @brief Switches active pane (focus moves between splits)
+ * @return 0 on success, -1 on failure
+ */
+int splitScreenSwitchPane(void);
+
+/**
+ * @brief Updates the active pane's buffer
+ * @param buffer_id New buffer ID for active pane
+ * @return 0 on success, -1 on failure
+ */
+int splitScreenSetPaneBuffer(int buffer_id);
+
+/**
+ * @brief Gets current screen layout
+ * @return Pointer to current ScreenLayout
+ */
+ScreenLayout *splitScreenGetLayout(void);
+
+/**
+ * @brief Gets active pane
+ * @return Pointer to active EditorPane
+ */
+EditorPane *splitScreenGetActivePane(void);
+
+#endif

include/syntax_highlighter.h

@@ -0,0 +1,21 @@
+#ifndef SYNTAX_HIGHLIGHTER_H_
+#define SYNTAX_HIGHLIGHTER_H_
+
+
+// Color codes that only affect foreground, preserving your background color
+#define COLOR_RESET         "\x1b[39m"            // Reset all (4 bytes)
+
+// Token types
+typedef enum {
+  TOKEN_KEYWORD,
+  TOKEN_TYPE,
+  TOKEN_STRING,
+  TOKEN_COMMENT,
+  TOKEN_NUMBER,
+  TOKEN_OPERATOR,
+  TOKEN_DEFAULT
+} TokenType;
+
+char *highlight_line(const char * line, int *length);
+
+#endif

include/terminal.h

@@ -4,8 +4,6 @@
 
 /* includes */
 
-#include "data.h"
-#include "define.h"
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -31,4 +29,8 @@ int getCursorPosition(int *rows, int *cols);
 
 int getWindowSize(int *rows, int *cols);
 
+char *keyToString(int key);
+
+void appDebug(const char *fmt, ...);
+
 #endif

include/utf8.h

@@ -0,0 +1,16 @@
+//
+// Created by Giorgio on 01/05/2026.
+//
+
+#ifndef BELUGA_UTF8_H
+#define BELUGA_UTF8_H
+#include <stdint.h>
+
+uint32_t readUtf8Char(void);
+int utf8Encode(uint32_t cp, char *buf);
+int utf8Seqlen(unsigned char c);
+int codepointWidth(uint32_t codepoint);
+uint32_t utf8Decode(const char** s);
+
+
+#endif //BELUGA_UTF8_H

install.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+
+
+echo "--- Welcome to Beluga installer ---"
+read -p "Do you want to start the installation ? (Y/n)" confirm && [[ $confirm == [yY] || $confirm == [yY][eE][sS] ]] || exit 1
+
+# Check dependencies
+
+if ! command -v "meson" &>/dev/null; then
+    echo "❌ Error: meson not found. Please install it first."
+    exit 1
+fi
+
+
+# Create config files
+
+echo "Create config files ..."
+mkdir -pv ~/.beluga/
+mkdir -pv ~/.beluga/assets/
+cp -rv ./assets/beluga.txt ~/.beluga/assets/
+mkdir -pv ~/.beluga/packages/
+mkdir -pv ~/.beluga/config/
+
+read -p "Do you want to replace your config file or keep it (init.lisp.bak) / (init.lisp.new) ? (Y/n)" confirm
+if [[ "$confirm" =~ ^[Yy]$ ]]; then
+    mv ~/.beluga/config/init.lisp  ~/.beluga/config/init.lisp.bak
+    cp -rv ./config/init.lisp ~/.beluga/config/
+else
+    cp -rv ./config/init.lisp ~/.beluga/config/init.lisp.new
+fi
+
+
+# Compile the project
+
+echo "Start compilation ..."
+meson setup build/
+meson compile -C build/
+
+# Add to path
+echo "Adding beluga to the path"
+sudo cp -f ./build/beluga /usr/local/bin/
+
+echo "Installation finish"
+echo "Check ~/.beluga/config/init.lisp for customization"

main.c

@@ -5,33 +5,43 @@
  * interactions. \version 0.1 \date 21 septembre 2024
  */
 
-#include <unistd.h>
-
 #define _DEFAULT_SOURCE
 #define _BSD_SOURCE
 #define _GNU_SOURCE
 
+#include "include/buffer.h"
+#include "include/split_screen.h"
+#include <string.h>
+#include <unistd.h>
+
 #include "include/data.h"
-#include "include/file_io.h"
 #include "include/init.h"
 #include "include/input.h"
-#include "include/output.h"
+#include "include/editor_op.h"
 #include "include/terminal.h"
 
 struct editorConfig E;
 
 int main(int argc, char *argv[]) {
 
+  char * splash_screen = (char *) calloc(256, sizeof(char));
+
   enableRawMode();
   initEditor();
   if (argc >= 2) {
-    E.state = READ_AND_WRITE;
-    editorOpen(argv[1]);
+    EditorPane *active = splitScreenGetActivePane();
+    active->buffer_id = bufferCreate(argv[1], READ_AND_WRITE);
   } else {
-    editorOpen("assets/beluga.txt");
-  }
+    strcat(splash_screen, getenv("HOME"));
+    strcat(splash_screen, "/.beluga/assets/beluga.txt");
 
-  editorSetStatusMessage("HELP: Ctrl-S = save | Ctrl-Q = quit");
+    appDebug("splash : %s\n", splash_screen);
+    EditorPane *active = splitScreenGetActivePane();
+    active->buffer_id = bufferCreate(splash_screen, READ_ONLY);
+  }
+  free(splash_screen);
+
+  editorSetStatusMessage("HELP: Ctrl-x Ctrl-s = save | Ctrl-x Ctrl-c = quit");
 
 
   while (1) {

meson.build

@@ -1,5 +1,5 @@
 project('beluga', 'c',
-  version : '1.1',
+  version : '2.3',
   default_options : [
     'c_std=none',
   ]
@@ -13,6 +13,7 @@ src_files = files(
   'main.c',
   'src/append_buffer.c',
   'src/editor_op.c',
+  'src/syntax_highlighter.c',
   'src/file_io.c',
   'src/init.c',
   'src/input.c',
@@ -20,10 +21,15 @@ src_files = files(
   'src/row_op.c',
   'src/terminal.c',
   'src/builtins.c',
+  'src/buffer.c',
+  'src/split_screen.c',
+  'src/utf8.c'
 )
 
 # Executable
 executable('beluga',
   src_files,
   dependencies: [m]
+)
+  dependencies: [m]
 )

src/append_buffer.c

@@ -1,7 +1,5 @@
 #include "../include/append_buffer.h"
 
-extern struct editorConfig E;
-
 void abAppend(struct abuf *ab, const char *s, int len) {
   char *new = realloc(ab->b, ab->len + len);
 

src/buffer.c

@@ -0,0 +1,477 @@
+/**
+ * @file buffer.c
+ * @brief Buffer management implementation for multiple open files
+ */
+
+#include "../include/buffer.h"
+#include "../include/file_io.h"
+#include "../include/editor_op.h"
+#include "../include/data.h"
+#include "include/split_screen.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#include "include/input.h"
+
+
+/**
+ * @brief Finds a buffer by filename
+ * @param filename The filename to search for
+ * @return Buffer ID if found, -1 if not found
+ */
+static int bufferFindByFilename(const char* filename)
+{
+    for (int i = 0; i < E.number_of_buffer; i++)
+    {
+        if (E.buffers[i].filename != NULL &&
+            strcmp(E.buffers[i].filename, filename) == 0)
+        {
+            return E.buffers[i].buffer_id;
+        }
+    }
+    return -1;
+}
+
+/**
+ * @brief Finds a buffer by ID
+ * @param buffer_id The buffer ID to find
+ * @return Pointer to buffer, NULL if not found
+ */
+struct buffer_t* bufferFindById(int buffer_id)
+{
+    for (int i = 0; i < E.number_of_buffer; i++)
+    {
+        if (E.buffers[i].buffer_id == buffer_id)
+        {
+            return &E.buffers[i];
+        }
+    }
+    return NULL;
+}
+
+/**
+ * @brief Creates a new buffer for a file
+ * @details Allocates buffer slot, loads file content, saves buffer metadata.
+ * If file is already open, switches to existing buffer instead.
+ * @param filename Path to the file
+ * @return Buffer ID on success, -1 on failure
+ */
+int bufferCreate(const char* filename, enum bufferStatus_e state)
+{
+    // Check if file is already open
+    const int existing_id = bufferFindByFilename(filename);
+    if (existing_id != -1)
+    {
+        return bufferSwitch(existing_id);
+    }
+
+    // Check if we have space for more buffers
+    if (E.number_of_buffer >= 64)
+    {
+        editorSetStatusMessage("Error: maximum buffers reached (64)");
+        return -1;
+    }
+
+    // Initialize new buffer
+    struct buffer_t* new_buf = &E.buffers[E.number_of_buffer];
+    new_buf->buffer_id = E.number_of_buffer;
+    new_buf->filename = strdup(filename);
+    new_buf->type = FILE_BUFF;
+    new_buf->state = state;
+    new_buf->x = 0;
+    new_buf->y = 0;
+    new_buf->dirty = 0; // New file starts clean
+
+    // Load file content using existing editorOpen
+    editorOpen(new_buf);
+
+    E.number_of_buffer++;
+
+    editorSetStatusMessage("Opened: %s (buffer %d)", filename, new_buf->buffer_id);
+    return new_buf->buffer_id;
+}
+
+/**
+ * @brief Switches to a specific buffer by ID
+ * @details Saves current buffer state, loads target buffer content and state.
+ * @param buffer_id The buffer ID to switch to
+ * @return 0 on success, -1 on failure
+ */
+int bufferSwitch(int buffer_id)
+{
+    struct buffer_t* target = bufferFindById(buffer_id);
+    if (target == NULL)
+    {
+        E.layout.panes[E.layout.active_pane].buffer_id = buffer_id;
+        editorSetStatusMessage("Error: buffer not found");
+        return -1;
+    }
+
+
+    editorSetStatusMessage("Switched to: %s (buffer %d)",
+                           target->filename, buffer_id);
+    return 0;
+}
+
+/**
+ * @brief Closes a buffer by ID
+ * @details Frees buffer resources and removes from buffer list.
+ * Prompts to save unsaved changes. If closing current buffer,
+ * switches to next available buffer.
+ * @param buffer_id The buffer ID to close
+ * @return 0 on success, -1 on failure
+ */
+int bufferClose(int buffer_id)
+{
+    struct buffer_t* buf = bufferFindById(buffer_id);
+    if (buf == NULL)
+    {
+        editorSetStatusMessage("Error: buffer not found");
+        return -1;
+    }
+
+    EditorPane* active = splitScreenGetActivePane();
+
+    // If this is the current buffer, find next buffer to switch to
+    if (active->buffer_id == buffer_id)
+    {
+        int next_id = -1;
+
+        // Try to switch to next buffer
+        for (int i = 0; i < E.number_of_buffer; i++)
+        {
+            if (E.buffers[i].buffer_id != buffer_id)
+            {
+                next_id = E.buffers[i].buffer_id;
+                break;
+            }
+        }
+
+        if (next_id != -1)
+        {
+            bufferSwitch(next_id);
+        }
+        else
+        {
+            // No other buffers, clear editor
+            editorCloseFile();
+        }
+    }
+
+    // Free buffer resources
+    free(buf->filename);
+    buf->filename = NULL;
+    buf->buffer_id = -1;
+
+    // Remove from buffer list by shifting
+    for (int i = 0; i < E.number_of_buffer; i++)
+    {
+        if (E.buffers[i].buffer_id == buffer_id)
+        {
+            for (int j = i; j < E.number_of_buffer - 1; j++)
+            {
+                E.buffers[j] = E.buffers[j + 1];
+            }
+            E.number_of_buffer--;
+            break;
+        }
+    }
+
+    editorSetStatusMessage("Closed buffer %d", buffer_id);
+    return 0;
+}
+
+/**
+ * @brief Gets the current active buffer
+ * @return Pointer to current buffer_t, NULL if none
+ */
+struct buffer_t* bufferGetCurrent(void)
+{
+    EditorPane* active = splitScreenGetActivePane();
+    return bufferFindById(active->buffer_id);
+}
+
+/**
+ * @brief Lists all open buffers
+ * @details Prints buffer information to status message
+ * @return Number of open buffers
+ */
+int bufferListAll(void)
+{
+    if (E.number_of_buffer == 0)
+    {
+        editorSetStatusMessage("No buffers open");
+        return 0;
+    }
+
+    char buf[256] = "";
+    int offset = 0;
+    EditorPane* active = splitScreenGetActivePane();
+
+    for (int i = 0; i < E.number_of_buffer; i++)
+    {
+        struct buffer_t* b = &E.buffers[i];
+        char marker = (b->buffer_id == active->buffer_id) ? '*' : ' ';
+        offset += snprintf(&buf[offset], sizeof(buf) - offset,
+                           "%c%d:%s ", marker, b->buffer_id,
+                           b->filename ? b->filename : "[No Name]");
+    }
+
+    editorSetStatusMessage("Buffers: %s", buf);
+    return E.number_of_buffer;
+}
+
+/**
+ * @brief Saves current buffer to disk
+ * @return 0 on success, -1 on failure
+ */
+int bufferSave(void)
+{
+    EditorPane* active = splitScreenGetActivePane();
+    if (active->buffer_id == -1)
+    {
+        editorSetStatusMessage("Error: no buffer active");
+        return -1;
+    }
+
+    editorSave();
+    return 0;
+}
+
+/**
+ * @brief Saves all buffers to disk
+ * @details Iterates through all buffers, saves each one
+ * @return 0 on success, -1 on failure
+ */
+int bufferSaveAll(void)
+{
+    int saved = 0;
+    int failed = 0;
+
+    for (int i = 0; i < E.number_of_buffer; i++)
+    {
+        if (bufferSwitch(E.buffers[i].buffer_id) == 0)
+        {
+            if (E.dirty && bufferSave() == 0)
+            {
+                saved++;
+            }
+        }
+        else
+        {
+            failed++;
+        }
+    }
+
+    editorSetStatusMessage("Saved %d buffers (%d failed)", saved, failed);
+    return (failed == 0) ? 0 : -1;
+}
+
+/**
+ * @brief Searches for a string in the document
+ * @details Prompts user for a search query, then searches forward from current
+ * cursor position. Updates cursor position to the first match found.
+ * @note Updates global editor state E (cursor position, row_offset)
+ * @note Search is case-sensitive and operates on rendered line content
+ * @note Searches begin from the line after current cursor position
+ * @see editorPrompt()
+ * @see editorRowRxToCx()
+ */
+void bufferFind(struct buffer_t* buf)
+{
+    appDebug("searching\n");
+    char* query = editorPrompt("Search: %s (ESC to cancel)", "", 0);
+
+    if (query == NULL)
+        return;
+    int i;
+    for (i = buf->y+1; i < buf->numrows; i++)
+    {
+        row_t* row = &buf->row[i];
+        char* match = strstr(row->chars, query);
+        if (match)
+        {
+            buf->y = i;
+            break;
+        }
+    }
+    free(query);
+}
+
+void bufferFindReverse(struct buffer_t* buf)
+{
+    appDebug("searching\n");
+    char* query = editorPrompt("Reverse search: %s (ESC to cancel)", "", 0);
+
+    if (query == NULL)
+        return;
+    int i;
+    if (!buf->y)
+        return;
+    for (i = buf->y - 1; i >= 0; i--)
+    {
+        row_t* row = &buf->row[i];
+        char* match = strstr(row->chars, query);
+        if (match)
+        {
+            buf->y = i;
+            break;
+        }
+    }
+    free(query);
+}
+
+void bufferInsertRow(struct buffer_t *buffer, int at, char *s, size_t len) {
+  if (at < 0 || at > buffer->numrows)
+    return;
+
+  row_t *tmp = realloc(buffer->row, sizeof(row_t) * (buffer->numrows + 1));
+  if (!tmp)
+    return;
+  buffer->row = tmp;
+
+  /* Shift existing rows to make room at 'at' — no at++ */
+  if (at < buffer->numrows) {
+    memmove(&buffer->row[at + 1], &buffer->row[at],
+            sizeof(row_t) * (buffer->numrows - at)); /* not -at+1 */
+  }
+
+  buffer->row[at].size  = len;
+  buffer->row[at].cap   = len + 1;
+  buffer->row[at].chars = malloc(len + 1);
+  if (!buffer->row[at].chars)
+    return;
+  memcpy(buffer->row[at].chars, s, len);
+  buffer->row[at].chars[len] = '\0'; /* always NUL-terminate */
+
+  buffer->numrows++;
+  buffer->dirty++;
+}
+
+void bufferFreeRow(row_t *row) { free(row->chars); }
+
+/**
+ * \fn editorRowInsertChar(erow *row, int at, int c)
+ * \param at Index of where we want to insert the char */
+
+void bufferRowInsertBytes(struct buffer_t *buffer, row_t *row, int at,
+                          const char *src, int n) {
+  if (buffer->state == READ_ONLY)
+    return;
+  if (row->size + n + 1 > row->cap) {
+    row->cap = (row->size + n + 1) * 2;
+    row->chars = realloc(row->chars, row->cap);
+  }
+  memmove(row->chars + at + n, row->chars + at, row->size - at);
+  memcpy(row->chars + at, src, n);
+  row->size += n;
+  row->chars = realloc(row->chars, row->size + 2);
+  ++buffer->dirty;
+}
+
+/**
+ * \fn bufferRowDelChar(struct bufferConfig *E, frow *frow, int at)
+ * \brief Delete the a char at the chosen position on the given row
+ * \param at Index of the char to delete
+ * \param row Row on operation is made */
+void bufferRowDelByte(struct buffer_t *buffer, row_t *row, int at, int n) {
+    if (buffer->state == READ_ONLY)
+        return;
+    if (at < 0 || at >= row->size)
+        return;
+  memmove(row->chars + at, row->chars + at + n, row->size - at - n);
+  row->size -= n;
+  row->chars[row->size] = '\0';
+  buffer->x -= n;
+  ++buffer->dirty;
+}
+
+
+void bufferInsertBytes(const char* src, int n)
+{
+    appDebug("bufferInsertBytes \r\n");
+    EditorPane* active = splitScreenGetActivePane();
+    struct buffer_t* buf = bufferFindById(active->buffer_id);
+    if (buf->y == buf->numrows)
+    {
+        bufferInsertRow(buf, buf->numrows, "", 0);
+    }
+    bufferRowInsertBytes(buf, &buf->row[buf->y], buf->x, src, n);
+    buf->x += n;
+}
+
+void bufferDelBytes(void)
+{
+    EditorPane* active = splitScreenGetActivePane();
+    struct buffer_t* buf = bufferFindById(active->buffer_id);
+
+    /* Nothing to delete */
+    if (buf->numrows == 0) return;
+    if (buf->x == 0 && buf->y == 0) return;
+
+    /* Use row_offset, not col_offset, for row indexing */
+    row_t* r = &buf->row[buf->y];
+
+    if (buf->x > 0)
+    {
+        int byte_end = editorRowCxToByte(r, buf->x);
+        int byte_start = editorRowCxToByte(r, buf->x - 1);
+        int char_width = byte_end - byte_start; /* byte width of the character */
+
+        bufferRowDelByte(buf, r, byte_start, char_width);
+        E.dirty = 1;
+    }
+    else
+    {
+        /* Merge current row into the previous one */
+        row_t* prev = &buf->row[buf->y - 1];  // FIX: was buf->y (same as r)
+        int prev_char_count = editorRowCharCount(prev, prev->size);
+
+        bufferRowInsertBytes(buf, prev, prev->size, r->chars, r->size);
+        free(r->chars);
+        r->chars = NULL;
+
+        memmove(&buf->row[buf->y],
+                &buf->row[buf->y + 1],
+                sizeof(row_t) * (buf->numrows - buf->y - 1));
+        buf->numrows--;
+
+        active->cursor_x = prev_char_count;
+        buf->x = prev_char_count;
+        active->cursor_y--;
+        buf->y--;
+        E.dirty = 1;
+    }
+}
+
+void bufferInsertNewLine(void) {
+    appDebug("Inserting new line\n");
+    EditorPane *active = splitScreenGetActivePane();
+    struct buffer_t *buf = bufferFindById(active->buffer_id);
+
+    appDebug("buf x %d\n", buf->x);
+
+    if (buf->y >= buf->numrows) {
+        /* Cursor is past the last row: just append a blank line */
+        bufferInsertRow(buf, buf->numrows, "", 0);
+    } else {
+        row_t *row = &buf->row[buf->y];
+
+        /* Insert the tail (from cursor to end) as a new row below */
+        bufferInsertRow(buf, buf->y + 1, &row->chars[buf->x], row->size - buf->x);
+
+        /* Re-fetch: realloc inside bufferInsertRow may have moved the array */
+        row = &buf->row[buf->y];
+
+        /* Truncate the current row at the cursor */
+        row->size           = buf->x;
+        row->chars[row->size] = '\0';
+        /* Do NOT touch row->cap — the allocation is still valid */
+    }
+
+    buf->y++;
+    buf->x = 0;
+    appDebug("Insert new line done\n");
+}

src/builtins.c

@@ -1,109 +1,296 @@
+/**
+ * @file builtins.c
+ * @brief Built-in Lisp functions for editor operations
+ * @details Provides Lisp bindings for core editor functionality including
+ * cursor movement, file operations, keybinding management, and text
+ * manipulation
+ */
+
 #include "../include/builtins.h"
-#include "../include/define.h"
-#include "../include/input.h"
-#include "../include/file_io.h"
-#include "../include/editor_op.h"
+#include "../include/buffer.h"
 #include "../include/data.h"
+#include "../include/define.h"
+#include "../include/editor_op.h"
+#include "../include/file_io.h"
+#include "../include/input.h"
+#include "../include/terminal.h"
+#include "../include/split_screen.h"
+#include "../include/completion.h"
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+/**
+ * @brief Finds a prefix configuration by name
+ * @details Searches the prefix array for a prefix matching the given name.
+ * Returns the first prefix (default) if no match is found.
+ * @param prefix_name Name of the prefix to search for (max 64 chars)
+ * @return Matching prefix_t structure, or E.prefix[0] if not found
+ * @note Updates global editor state E
+ */
+struct prefix_t find_prefix(const char prefix_name[64]) {
+  int i = E.number_of_prefix + 1;
+  while (i--) {
+    if (!strcmp(prefix_name, E.prefix[i].prefix_name)) {
+      return E.prefix[i];
+    }
+  }
+  return E.prefix[0];
+}
+
+/**
+ * @brief Lisp function to bind a command to a key sequence
+ * @details Registers a keybinding with an associated Lisp command and optional
+ * prefix modifier. Dynamically extends the keybind array.
+ * @param args Lisp list of 3 arguments: (key-sequence command prefix-name)
+ *        - key_sequence (string): The key or key combination to bind
+ *        - command (Lisp): The Lisp command/function to execute
+ *        - prefix_name (string): Prefix modifier name
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @note Updates global editor state E (key_binds array)
+ */
 Lisp mapKey(Lisp args, LispError *e, LispContext ctx) {
+  /*
+   * 3 arguments keybind command prefix
+   */
   const char *key_sequence = lisp_string(lisp_car(args));
   args = lisp_cdr(args);
   // second argument
-  Lisp func = lisp_car(args);
+  const Lisp func = lisp_car(args);
 
-  E.key_binds =
-      (struct keyBind_t *)realloc(E.key_binds, ++E.number_of_keybinds * sizeof(struct keyBind_t));
-  E.key_binds[E.number_of_keybinds - 1].key_sequence = (char *) malloc(50 * sizeof(char));
+  E.key_binds = (struct keyBind_t *)realloc(
+      E.key_binds, ++E.number_of_keybinds * sizeof(struct keyBind_t));
+  E.key_binds[E.number_of_keybinds - 1].key_sequence =
+      (char *)malloc(50 * sizeof(char));
 
   strncpy(E.key_binds[E.number_of_keybinds - 1].key_sequence, key_sequence, 50);
 
   E.key_binds[E.number_of_keybinds - 1].command = func;
 
+  // Third argument
+  args = lisp_cdr(args);
+  const char *prefix_name = lisp_string(lisp_car(args));
+  struct prefix_t prefix = find_prefix(prefix_name);
+
+  E.key_binds[E.number_of_keybinds - 1].prefix_id = prefix.prefix_id;
+
   return lisp_null();
 }
 
+/**
+ * @brief Lisp function to move cursor in a specified direction
+ * @details Moves the editor cursor up, down, left, or right based on direction
+ * string.
+ * @param args Lisp list with one argument: direction string
+ *        - "u": up, "d": down, "r": right, "l": left
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return Lisp boolean indicating whether movement was valid
+ * @note Updates global editor state E
+ * @see editorMoveCursor()
+ */
 Lisp moveCursor(Lisp args, LispError *e, LispContext ctx) {
-  fprintf(stderr, "Cursor is moving\n");
   const char *direction = lisp_string(lisp_car(args));
+  int is_in = 0;
   switch (direction[0]) {
   case 'u':
-    editorMoveCursor(ARROW_UP);
+    is_in = editorMoveCursor(ARROW_UP);
     break;
   case 'd':
-    editorMoveCursor(ARROW_DOWN);
+    is_in = editorMoveCursor(ARROW_DOWN);
     break;
   case 'r':
-    editorMoveCursor(ARROW_RIGHT);
+    is_in = editorMoveCursor(ARROW_RIGHT);
     break;
   case 'l':
-    editorMoveCursor(ARROW_LEFT);
+    is_in = editorMoveCursor(ARROW_LEFT);
     break;
   }
-
-
-  return lisp_null();
+  appDebug("move lisp %d\n", is_in);
+  return lisp_make_bool(is_in);
 }
 
-Lisp editorQuit(Lisp args, LispError* e, LispContext ctx) {
+/**
+ * @brief Frees all dynamically allocated editor structures
+ * @details Releases memory for prefix table, keybinds, filename, and all rows.
+ * Called during shutdown to prevent memory leaks.
+ * @note Updates global editor state E
+ */
+void free_structs(void) {
+  int i, j;
+  free(E.prefix);
+  for (i = 0; i < E.number_of_keybinds; ++i) {
+    free(E.key_binds[i].key_sequence);
+  }
+  free(E.key_binds);
+  // free layout
+  free(E.layout.panes);
+
+  // Free buffers
+  for (i = 0; i < E.number_of_buffer; ++i) {
+    free(E.buffers[i].filename);
+    for (j = 0; j < E.buffers[i].numrows; ++j) {
+      free(E.buffers[i].row[j].chars);
+    }
+    free(E.buffers[i].row);
+  }
+
+  free(E.init_file_path);
+  fclose(E.fd_init_file);
+}
+
+/**
+ * @brief Lisp function to quit the editor
+ * @details Closes editor with unsaved changes protection. Prompts user to
+ * confirm quit after multiple attempts if file is dirty. Cleans up resources
+ * and restores terminal.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null() (never returns on successful exit)
+ * @note Calls exit(0) to terminate program
+ * @note Updates quit_times_buffer counter
+ * @see free_structs()
+ */
+Lisp editorQuit(Lisp args, LispError *e, LispContext ctx) {
   if (E.dirty && E.quit_times_buffer > 0) {
     editorSetStatusMessage("WARNING! Changes hasn't been saved. Press Ctrl-Q "
                            "another time to quit.");
     --E.quit_times_buffer;
     return lisp_null();
   }
+  free_structs();
   write(STDOUT_FILENO, "\x1b[2J", 4);
   write(STDOUT_FILENO, CURSOR_TOP_LEFT, 3);
   disableRawMode();
+  lisp_shutdown(E.ctx);
   exit(0);
 
   return lisp_null();
-
-  
 }
 
+/**
+ * @brief Lisp function to save the current file
+ * @details Wrapper around editorSave() for use in Lisp keybindings.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @see editorSave()
+ */
 
-Lisp l_editorSave(Lisp args, LispError* e, LispContext ctx) {
-
-  editorSave();
-  
-  return lisp_null();
-
-  
-}
-
-Lisp l_editorInsertNewLine(Lisp args, LispError* e, LispContext ctx) {
-
-  editorInsertNewLine();
-  
-  return lisp_null();
-
-  
-}
-
-Lisp moveCursorBeginLine(Lisp args, LispError *e, LispContext ctx) {
-  E.cursor_x = 0;
-  return lisp_null();
-}
-
-Lisp moveCursorEndLine(Lisp args, LispError* e, LispContext ctx) {
-  if (E.cursor_y < E.numrows) {
-    E.cursor_x = E.row[E.cursor_y].size;
+Lisp l_editorSplitScreenVertical(Lisp args, LispError *e, LispContext ctx) {
+  if (E.number_of_buffer >= 2) {
+    splitScreenVertical(E.buffers[0].buffer_id, E.buffers[1].buffer_id);
+  } else {
+    editorSetStatusMessage("Need at least 2 buffers open");
   }
   return lisp_null();
 }
 
+Lisp l_editorSave(Lisp args, LispError *e, LispContext ctx) {
+
+  editorSave();
 
-Lisp deletePreviousChar(Lisp args, LispError* e, LispContext ctx) {
-  editorDelChar();
   return lisp_null();
 }
 
-Lisp editorMoveCursorPageUp(Lisp args, LispError* e, LispContext ctx) {
-  E.cursor_y = E.row_offset;
+/**
+ * @brief Lisp function to insert a new line at cursor
+ * @details Wrapper around editorInsertNewLine() for use in Lisp keybindings.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @see editorInsertNewLine()
+ */
+Lisp l_editorInsertNewLine(Lisp args, LispError *e, LispContext ctx) {
+
+  bufferInsertNewLine();
+
+  return lisp_null();
+}
+
+/**
+ * @brief Lisp function to insert a tab (spaces) at cursor
+ * @details Inserts TAB_LENGTH spaces at the current cursor position.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @note Uses E.constantes.TAB_LENGTH for indentation width
+ */
+Lisp l_editorInserTab(Lisp args, LispError *e, LispContext ctx) {
+  for (int i = 0; i < E.constantes.TAB_LENGTH; ++i) {
+    bufferInsertBytes(" ", 1);
+  }
+
+  return lisp_null();
+}
+
+/**
+ * @brief Lisp function to move cursor to beginning of line
+ * @details Moves cursor to column 0 of the current line.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @note Updates global editor state E
+ */
+Lisp moveCursorBeginLine(Lisp args, LispError *e, LispContext ctx) {
+  EditorPane *active = splitScreenGetActivePane();
+  struct buffer_t *buf = bufferFindById(active->buffer_id);
+  buf->x = 0;
+  return lisp_null();
+}
+
+/**
+ * @brief Lisp function to move cursor to end of line
+ * @details Moves cursor to the end of the current line content.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @note Updates global editor state E
+ */
+Lisp moveCursorEndLine(Lisp args, LispError *e, LispContext ctx) {
+  EditorPane *active = splitScreenGetActivePane();
+  struct buffer_t *buf = bufferFindById(active->buffer_id);
+  buf->x = buf->row[buf->y].size;
+  return lisp_null();
+}
+
+/**
+ * @brief Lisp function to delete character before cursor
+ * @details Wrapper around editorDelChar() for use in Lisp keybindings.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @see editorDelChar()
+ */
+Lisp deletePreviousChar(Lisp args, LispError *e, LispContext ctx) {
+  bufferDelBytes();
+  return lisp_null();
+}
+
+/**
+ * @brief Lisp function to move cursor up by one screen
+ * @details Scrolls up one full screen height, moving cursor to top of visible
+ * area.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @note Updates global editor state E
+ * @see editorMoveCursor()
+ */
+Lisp editorMoveCursorPageUp(Lisp args, LispError *e, LispContext ctx) {
+  EditorPane *active = splitScreenGetActivePane();
+  active->cursor_y = active->y_offset;
   int times = E.screenrows;
   while (--times) {
     editorMoveCursor(ARROW_UP);
@@ -111,10 +298,23 @@ Lisp editorMoveCursorPageUp(Lisp args, LispError* e, LispContext ctx) {
   return lisp_null();
 }
 
-Lisp editorMoveCursorPageDown(Lisp args, LispError* e, LispContext ctx) {
-  E.cursor_y = E.row_offset + E.screenrows - 1;
-  if (E.cursor_y > E.numrows) {
-    E.cursor_y = E.numrows;
+/**
+ * @brief Lisp function to move cursor down by one screen
+ * @details Scrolls down one full screen height, moving cursor to bottom of
+ * visible area.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @note Updates global editor state E
+ * @see editorMoveCursor()
+ */
+Lisp editorMoveCursorPageDown(Lisp args, LispError *e, LispContext ctx) {
+  EditorPane *active = splitScreenGetActivePane();
+  struct buffer_t *buffer = bufferFindById(active->buffer_id);
+  active->cursor_y = active->y_offset + E.screenrows - 1;
+  if (active->cursor_y > buffer->numrows) {
+    active->cursor_y = buffer->numrows;
   }
   int times = E.screenrows;
   while (--times) {
@@ -124,18 +324,238 @@ Lisp editorMoveCursorPageDown(Lisp args, LispError* e, LispContext ctx) {
   return lisp_null();
 }
 
+/**
+ * @brief Lisp function to open a file
+ * @details Prompts user for filename and opens the file for editing.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @note Updates global editor state E
+ * @see editorOpen()
+ * @see editorPrompt()
+ */
 Lisp editorOpenFile(Lisp args, LispError *e, LispContext ctx) {
-  char *filename = editorPrompt("Path : %s");
-  if (filename)
-    editorOpen(filename);
+  char *filename = editorPrompt("Open : %s", getenv("PWD"), 1);
+  if (filename) {
+    //    editorOpen(filename);
+    EditorPane *active = splitScreenGetActivePane();
+    active->buffer_id = bufferCreate(filename, READ_AND_WRITE);
+  }
+  free(filename);
 
   return lisp_null();
 }
 
-
+/**
+ * @brief Lisp function to insert a character
+ * @details Extracts a character from Lisp string argument and inserts it at
+ * cursor.
+ * @param args Lisp list with one string argument
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @note Uses first character of the string argument
+ */
 Lisp editorPrintC(Lisp args, LispError *e, LispContext ctx) {
-  char c = lisp_char(lisp_car(args));
-  editorInsertChar(c);
+  const char *src = lisp_string(lisp_car(args));
+  bufferInsertBytes(src, strlen(src));
   return lisp_null();
 }
 
+/**
+ * @brief Lisp function to load and execute a package
+ * @details Loads a Lisp package from the user's packages directory
+ * (~/.beluga/packages/<package_name>/init.lisp) and evaluates it.
+ * @param args Lisp list with one argument: package name (string)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @note Package files must be valid Lisp code
+ * @note Package directory defaults to ~/.beluga/packages/
+ */
+Lisp addPackage(Lisp args, LispError *e, LispContext ctx) {
+  const char *package_name = lisp_string(lisp_car(args));
+  appDebug("%s\n", package_name);
+  char *package_dir = (char *)calloc(256, sizeof(char));
+  FILE *fd_package = NULL;
+  strcat(package_dir, getenv("HOME"));
+  strcat(package_dir, "/.beluga/packages/");
+  strcat(package_dir, package_name);
+  strcat(package_dir, "/init.lisp");
+  appDebug("%s\n", package_dir);
+  fd_package = fopen(package_dir, "r");
+  lisp_eval(lisp_read_file(fd_package, &E.ctx_error, E.ctx), &E.ctx_error,
+            E.ctx);
+  fclose(fd_package);
+  free(package_dir);
+
+  return lisp_null();
+}
+
+Lisp editorSwitchNextBuffer(Lisp args, LispError *e, LispContext ctx) {
+  appDebug("switch buffer\n");
+  if (E.number_of_buffer > 0) {
+    EditorPane *active = splitScreenGetActivePane();
+    int next_idx = (active->buffer_id + 1) % E.number_of_buffer;
+    active->buffer_id = next_idx;
+  }
+
+  return lisp_null();
+}
+
+Lisp editorSwitchNextPane(Lisp args, LispError *e, LispContext ctx) {
+  splitScreenSwitchPane();
+  return lisp_null();
+}
+
+Lisp editorUnifiedPanes(Lisp args, LispError *e, LispContext ctx) {
+  if (E.layout.num_panes - 1) {
+    splitScreenUnify();
+  }
+  return lisp_null();
+}
+
+/**
+ * @brief Lisp function to search for text
+ * @details Wrapper around editorFind() for use in Lisp keybindings.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @see editorFind()
+ */
+Lisp bufferFind_L(Lisp args, LispError *e, LispContext ctx) {
+  appDebug("LispFind\n");
+  EditorPane *active = splitScreenGetActivePane();
+  struct buffer_t *buffer = bufferFindById(active->buffer_id);
+  bufferFind(buffer);
+  return lisp_null();
+}
+
+/**
+ * @brief Lisp function to search for text
+ * @details Wrapper around editorFind() for use in Lisp keybindings.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @see editorFind()
+ */
+Lisp bufferFindReverse_L(Lisp args, LispError *e, LispContext ctx) {
+  appDebug("LispFind\n");
+  EditorPane *active = splitScreenGetActivePane();
+  struct buffer_t *buffer = bufferFindById(active->buffer_id);
+  bufferFindReverse(buffer);
+  return lisp_null();
+}
+
+/**
+ * @brief Lisp function to read character at cursor
+ * @details Returns the character at the current cursor position as a Lisp
+ * character. Returns 'a' if at end of line.
+ * @param args Lisp arguments (unused)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return Lisp character object representing the character at cursor
+ */
+Lisp editorReadChar_L(Lisp args, LispError *e, LispContext ctx) {
+  Lisp returned_char;
+  EditorPane *active = splitScreenGetActivePane();
+  struct buffer_t *buffer = bufferFindById(active->buffer_id);
+  if (buffer->row[buffer->y].chars[buffer->x] == 0) {
+    returned_char = lisp_make_char('a');
+  } else {
+    returned_char = lisp_make_char(buffer->row[buffer->y].chars[buffer->x]);
+  }
+  return returned_char;
+}
+
+/**
+ * @brief Lisp function to set the current prefix mode
+ * @details Changes the editor's prefix state to a named prefix, affecting which
+ * keybindings are active. Updates status message to show active prefix.
+ * @param args Lisp list with one argument: prefix name (string)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @note Updates global editor state E (prefix_state)
+ * @see find_prefix()
+ */
+Lisp editorSetPrefix(Lisp args, LispError *e, LispContext ctx) {
+  /*
+   * Set the prefix state of editor to the prefix in argument
+   */
+  const char *prefix_name = lisp_string(lisp_car(args));
+  struct prefix_t prefix = find_prefix(prefix_name);
+  E.prefix_state = prefix.prefix_id;
+  editorSetStatusMessage("prefix %s", prefix.prefix_name);
+  appDebug("%s set\n", prefix_name);
+
+  return lisp_null();
+}
+
+/**
+ * @brief Lisp function to define a new prefix modifier
+ * @details Registers a named prefix modifier that can be used with keybindings
+ * to create context-aware command sequences (e.g., Ctrl-X as a prefix).
+ * @param args Lisp list with one argument: prefix name (string, max 64 chars)
+ * @param e Error pointer for Lisp error handling
+ * @param ctx Lisp context
+ * @return lisp_null()
+ * @note Updates global editor state E (prefix array)
+ */
+Lisp editorPrefix(Lisp args, LispError *e, LispContext ctx) {
+  E.prefix = (struct prefix_t *)realloc(E.prefix, (++(E.number_of_prefix) + 1) *
+                                                      sizeof(struct prefix_t));
+  E.prefix[E.number_of_prefix].prefix_id = E.number_of_prefix;
+  strncpy(E.prefix[E.number_of_prefix].prefix_name, lisp_string(lisp_car(args)),
+          64);
+  return lisp_null();
+}
+
+Lisp editorPaste(Lisp args, LispError *e, LispContext ctx)
+{
+  const char *char_to_paste = editorGetClipboard();
+  appDebug("editor-paste, %s\n", char_to_paste);
+  bufferInsertBytes(char_to_paste, (int) strlen(char_to_paste));
+  return lisp_null();
+}
+
+Lisp editorCutEndLine(Lisp args, LispError *e, LispContext ctx)
+{
+  EditorPane *active = splitScreenGetActivePane();
+  struct buffer_t *buffer = bufferFindById(active->buffer_id);
+  int bytes_to_delete = buffer->row[buffer->y].size - buffer->x;
+  editorSetClipboard(&buffer->row[buffer->y].chars[buffer->x], bytes_to_delete);
+  buffer->x = buffer->row[buffer->y].size;
+  while (bytes_to_delete--)
+  {
+    bufferDelBytes();
+  }
+  return lisp_null();
+}
+
+Lisp editorMoveBegBuffer(Lisp args, LispError *e, LispContext ctx)
+{
+  EditorPane *active = splitScreenGetActivePane();
+  struct buffer_t *buffer = bufferFindById(active->buffer_id);
+  buffer->x = 0;
+  buffer->y = 0;
+  return lisp_null();
+}
+
+Lisp editorMoveEndBuffer(Lisp args, LispError *e, LispContext ctx)
+{
+  EditorPane *active = splitScreenGetActivePane();
+  struct buffer_t *buffer = bufferFindById(active->buffer_id);
+  buffer->x = buffer->row[buffer->numrows-1].size;
+  buffer->y = buffer->numrows-1;
+  return lisp_null();
+}
+
+Lisp editorAutoComplete(Lisp args, LispError *e, LispContext ctx)
+{
+  createContextBuffer(E.cursor_x - 2, E.cursor_y + 1, "hello");
+  return lisp_null();
+}

src/editor_op.c

@@ -1,47 +1,130 @@
 #include "../include/editor_op.h"
+
+#include <stdarg.h>
+
 #include "../include/row_op.h"
+#include "../include/buffer.h"
+#include "../include/data.h"
+#include "../include/split_screen.h"
+#include "../include/terminal.h"
+#include "../include/utf8.h"
 
 
 extern struct editorConfig E;
 
-void editorInsertChar(int c) {
-    if (E.cursor_y == E.numrows) {
-      editorInsertRow(E.numrows, "", 0);
+
+/**
+ * @brief Sets a temporary status message for display
+ * @details Formats and stores a message that will be displayed in the message
+ * bar for 5 seconds. Uses printf-style variable argument formatting.
+ * @param fmt Printf-style format string
+ * @param ... Variable arguments for format string
+ * @note Updates global editor state E (status_msg, status_msg_time)
+ * @see editorDrawMessageBar()
+ */
+void editorSetStatusMessage(const char* fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    vsnprintf(E.status_msg, E.screencols, fmt, ap);
+    va_end(ap);
+    E.status_msg_time = time(NULL);
+}
+
+/**
+ * @brief Moves the cursor based on arrow key input
+ * @details Updates cursor position (E.cursor_x, E.cursor_y) based on the given
+ * key direction. Handles line wrapping and boundary conditions. Prevents cursor
+ * from exceeding line lengths.
+ * @param key The arrow key code (ARROW_UP, ARROW_DOWN, ARROW_LEFT, ARROW_RIGHT)
+ * @return 1 if cursor movement was valid, 0 if cursor was constrained to line boundary
+ * @note Updates global editor state E
+ */
+int editorMoveCursor(int key) {
+    EditorPane *active = splitScreenGetActivePane();
+    struct buffer_t *buf = bufferFindById(active->buffer_id);
+    row_t *row = &buf->row[buf->y];
+    switch (key) {
+    case ARROW_RIGHT:
+        if (row && buf->x < row->size) {
+            int len = utf8Seqlen(row->chars[buf->x]);
+            buf->x += len;
+        } else if (row && buf->y < buf->numrows) {
+            buf->y++;
+            buf->x = 0;
+        }
+        break;
+    case ARROW_DOWN:
+        if (buf->y < buf->numrows) {
+
+            buf->y++;
+        }
+        break;
+    case ARROW_UP:
+        if (buf->y != 0) {
+            --buf->y;
+        }
+        break;
+    case ARROW_LEFT:
+        if (buf->x != 0) {
+            --buf->x;
+        } else if (buf->y > 0) {
+            --buf->y;
+            buf->x = buf->row[buf->y].size;
+        }
+        break;
     }
-    editorRowInsertChar(&E.row[E.cursor_y], E.cursor_x, c);
-    E.cursor_x++;
+    return 1;
 }
 
-void editorInsertNewLine() {
-  erow *row;
-  if (!E.cursor_x) {
-    editorInsertRow(E.cursor_y, "", 0);
-  } else {
-    row = &E.row[E.cursor_y];
-    editorInsertRow(E.cursor_y + 1, &row->chars[E.cursor_x],
-                    row->size - E.cursor_x);
-    row = &E.row[E.cursor_y];
-    row->size = E.cursor_x;
-    row->chars[row->size] = '\0';
-    editorUpdateRow(row);
-  }
-  ++E.cursor_y;
-  E.cursor_x = 0;
+char *editorGetClipboard(void) {
+    FILE *pipe = popen(CLIPBOARD_PASTE_CMD, "r");
+    if (!pipe) return NULL;
+
+    size_t cap = 4096;
+    size_t len = 0;
+    char *buf = malloc(cap);
+
+    int c;
+    while ((c = fgetc(pipe)) != EOF) {
+        if (len + 1 >= cap) {
+            cap *= 2;
+            buf = realloc(buf, cap);
+        }
+        buf[len++] = (char)c;
+    }
+    buf[len] = '\0';
+    pclose(pipe);
+    return buf; // caller must free
 }
 
-void editorDelChar() {
-  erow *row;
-  if (E.cursor_y == E.numrows || !(E.cursor_x || E.cursor_y)) {
-    return;
-  }
-  row = &E.row[E.cursor_y];
-  if (E.cursor_x > 0) {
-    editorRowDelchar(row, E.cursor_x - 1);
-    --E.cursor_x;
-  } else {
-    E.cursor_x = E.row[E.cursor_y - 1].size;
-    editorRowAppendString(&E.row[E.cursor_y - 1], row->chars, row->size);
-    editorDelRow(E.cursor_y);
-    --E.cursor_y;
-  }
+void editorSetClipboard(const char *text, int len) {
+    FILE *pipe = popen(CLIPBOARD_COPY_CMD, "w");
+    if (!pipe) return;
+    fwrite(text, 1, len, pipe);
+    pclose(pipe);
 }
+
+int editorRowCxToByte(const row_t *row, int cursor_x) {
+    int i = 0, col = 0;
+    while (col < cursor_x && i < row->size) {
+        int sl = utf8Seqlen((unsigned char)row->chars[i]);
+        if (sl < 1)
+            sl = 1;
+        col++;
+        i += sl;
+    }
+    return i;
+}
+
+int editorRowCharCount(row_t *row, int x) {
+    int n = 0, i = 0;
+    while (i < x && i < row->size) {
+        int sl = utf8Seqlen((unsigned char)row->chars[i]);
+        if (sl < 1)
+            sl = 1;
+        n++;
+        i += sl;
+    }
+    return n;
+}

src/file_io.c

@@ -1,112 +1,130 @@
+/**
+ * @file file_io.c
+ * @brief File I/O operations module for the Beluga text editor
+ * @details Handles file loading, saving, searching, and buffer management.
+ * Provides functionality for opening/closing files, persisting changes to disk,
+ * and searching for text patterns within the document.
+ */
+
 #include "../include/file_io.h"
+#include "../include/editor_op.h"
 #include "../include/input.h"
-#include "../include/output.h"
+#include "../include/buffer.h"
+#include "../include/data.h"
+#include "../include/split_screen.h"
+#include "../include/row_op.h"
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include <unistd.h>
+#include <errno.h>
 
-extern char *strdup(const char *);
-extern ssize_t getline(char **restrict lineptr, size_t *restrict n,
-                       FILE *restrict stream);
-extern int ftruncate(int fd, off_t length);
 extern struct editorConfig E;
 
-char *editorRowsToString(int *buffer_len) {
-    int tot_len = 0;
-    int j;
-    char *buf;
-    char *p;
-
-    for (j = 0; j < E.numrows; ++j) {
-        tot_len += E.row[j].size + 1;
-    }
-    *buffer_len = tot_len;
-    buf = malloc(tot_len);
-    p = buf;
-    for (j = 0; j < E.numrows; ++j) {
-        memcpy(p, E.row[j].chars, E.row[j].size);
-        p += E.row[j].size;
-        *p = '\n';
-        p++;
-    }
-
-    return buf;
-}
-
+/**
+ * @brief Closes the current file and resets editor state
+ * @details Clears all rows, resets cursor position, scroll offsets, and file
+ * metadata. Does not prompt to save unsaved changes.
+ * @note Updates global editor state E
+ */
 void editorCloseFile(void) {
-    E.cursor_x = 0;
-    E.cursor_y = 0;
-    E.rx = 0;
-    E.row_offset = 0;
-    E.col_offset = 0;
-    E.numrows = 0;
-    E.row = NULL;
-    E.dirty = 0;
-    E.filename = NULL;
-    E.status_msg[0] = '\0';
-    E.status_msg_time = 0;
+  EditorPane *active = splitScreenGetActivePane();
+  struct buffer_t *buf = bufferFindById(active->buffer_id);
+  active->cursor_x = 0;
+  active->cursor_y = 0;
+  active->x_offset = 0;
+  active->y_offset = 0;
+  for (int i = 0; i < buf->numrows; ++i) {
+    free(buf->row[i].chars);
+  }
+  buf->numrows = 0;
+  free(buf->row);
+  buf->row = NULL;
+  buf->dirty = 0;
+  free(buf->filename);
+  buf->filename = NULL;
+  E.status_msg[0] = '\0';
+  E.status_msg_time = 0;
 }
 
-void editorOpen(char *filename) {
-    FILE *fp;
+/**
+ * @brief Opens a file for editing
+ * @details Loads file content into editor rows, one line per row. If another
+ * file is already open, it is closed first (without saving). File is opened in
+ * a+ (read/append) mode to allow both reading and modification.
+ * @param filename Path to the file to open (relative or absolute)
+ * @note Updates global editor state E
+ * @note Calls die() on file open failure
+ * @note Newline characters are stripped from loaded lines
+ * @see editorInsertRow()
+ */
+void editorOpen(struct buffer_t* buffer) {
+  FILE *fp;
 
-    // Test if a file is already open
-    if (E.filename != NULL) {
-        editorCloseFile();
-        E.state = READ_AND_WRITE;
-    }
-
-    free(E.filename);
-    E.filename = strdup(filename);
-
-    fp = fopen(filename, "a+");
-    if (!fp)
-        die("fopen");
-
-    char *line = NULL;
-    size_t line_cap = 0;
-    ssize_t line_len;
-
-    while ((line_len = getline(&line, &line_cap, fp)) != -1) {
-        while (line_len > 0 &&
-               (line[line_len - 1] == '\n' || line[line_len - 1] == '\r')) {
-            --line_len;
-        }
-        editorInsertRow(E.numrows, line, line_len);
+  fp = fopen(buffer->filename, "a+");
+  if (!fp)
+    die("fopen");
+
+  char *line = NULL;
+  size_t line_cap;
+  ssize_t line_len;
+
+  rewind(fp);
+
+  while ((line_len = getline(&line, &line_cap, fp)) != -1) {
+    while (line_len > 0 &&
+           (line[line_len - 1] == '\n' || line[line_len - 1] == '\r')) {
+      --line_len;
     }
+    appDebug("line %s\n", line);
+    bufferInsertRow(buffer, buffer->numrows, line, line_len);
     free(line);
-    fclose(fp);
-    E.dirty = 0;
+    line = NULL;
+  }
+  free(line);
+  fclose(fp);
+  E.dirty = 0;
 }
 
+/**
+ * @brief Saves the current file to disk
+ * @details Prompts for filename if not set, converts all rows to a buffer,
+ * writes to disk using open/ftruncate/write, and updates dirty flag.
+ * Displays status messages on success or failure.
+ * @note Updates global editor state E (dirty flag)
+ * @note If no filename is set, prompts user via editorPrompt()
+ * @note Uses O_RDWR | O_CREAT with mode 0644
+ * @see editorRowsToString()
+ */
 void editorSave() {
-    int len;
-    char *buf;
-    int fd;
-    if (E.filename == NULL) {
-        E.filename = editorPrompt("Save as: %s (ESC to cancel)");
-        if (E.filename == NULL) {
-            editorSetStatusMessage("Save aborted");
-            return;
-        }
+  EditorPane *active = splitScreenGetActivePane();
+  struct buffer_t *buffer = bufferFindById(active->buffer_id);
+  int len;
+  int fd;
+  if (buffer->filename == NULL) {
+    buffer->filename = editorPrompt("Save as: %s (ESC to cancel)", "", 1);
+    if (buffer->filename == NULL) {
+      editorSetStatusMessage("Save aborted");
+      return;
     }
-    buf = editorRowsToString(&len);
-    fd = open(E.filename, O_RDWR | O_CREAT, 0644);
-    if (fd != -1) {
-        if (ftruncate(fd, len) != -1) {
-            if (write(fd, buf, len) == len) {
-                close(fd);
-                free(buf);
-                E.dirty = 0;
-                editorSetStatusMessage("%d bytes written to disk", len);
-                return;
-            }
-        }
+  }
+  fd = open(buffer->filename, O_RDWR | O_CREAT, 0644);
+  if (fd != -1) {
+    for (int i = 0; i < buffer->numrows; ++i)
+    {
+      len = strlen(buffer->row[i].chars);
+      if (write(fd, buffer->row[i].chars, len) != len) {
         close(fd);
+        editorSetStatusMessage("Can't save! I/O error: %s", strerror(errno));
+
+        return;
+      }
+      write(fd, "\n", 1);
     }
-    free(buf);
-    editorSetStatusMessage("Can't save! I/O error: %s", strerror(errno));
+    buffer->dirty = 0;
+    close(fd);
+  }
+  editorSetStatusMessage("File saved");
 }

src/init.c

@@ -1,61 +1,60 @@
 #include "../include/init.h"
+#include "../include/builtins.h"
+#include "../include/color.h"
 #include "../include/data.h"
 #include "../include/terminal.h"
-#include "../include/builtins.h"
+#include "../include/split_screen.h"
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
 #define LISP_IMPLEMENTATION
 #include "../include/lisp.h"
 #include "../include/lisp_lib.h"
 
-extern struct editorConfig;
-
+struct editorConfig;
 
 void registerBuiltin(char *key_sequence, LispCFunc f) {
   lisp_env_define(E.ctx.p->env, lisp_make_symbol(key_sequence, E.ctx),
                   lisp_make_func(f), E.ctx);
-  
+
 }
 
 void initBuiltins() {
-  // move cursor
-  registerBuiltin("MOVE-CURSOR", moveCursor);
-  registerBuiltin("MAP-KEY", mapKey);
-  registerBuiltin("EDITOR-QUIT", editorQuit);
-  registerBuiltin("EDITOR-SAVE", l_editorSave);
-  registerBuiltin("EDITOR-INSERT-NEW-LINE", l_editorInsertNewLine);
-  registerBuiltin("MOVE-CURSOR-BEG-LINE", moveCursorBeginLine);
-  registerBuiltin("MOVE-CURSOR-END-LINE", moveCursorEndLine);
-  registerBuiltin("EDITOR-DELETE-PREVIOUS-CHAR", deletePreviousChar);
-  registerBuiltin("MOVE-CURSOR-PAGE-UP", editorMoveCursorPageUp);
-  registerBuiltin("MOVE-CURSOR-PAGE-DOWN", editorMoveCursorPageDown);
-  registerBuiltin("EDITOR-OPEN-FILE", editorOpenFile);
-  registerBuiltin("EDITOR-INSERT-CHAR", editorPrintC);
+  // Registering C functions as lisp macro
+  registerBuiltin("move-cursor", moveCursor);
+  registerBuiltin("map-key", mapKey);
+  registerBuiltin("editor-quit", editorQuit);
+  registerBuiltin("editor-save", l_editorSave);
+  registerBuiltin("editor-insert-new-line", l_editorInsertNewLine);
+  registerBuiltin("move-cursor-beg-line", moveCursorBeginLine);
+  registerBuiltin("move-cursor-end-line", moveCursorEndLine);
+  registerBuiltin("editor-delete-previous-char", deletePreviousChar);
+  registerBuiltin("move-cursor-page-up", editorMoveCursorPageUp);
+  registerBuiltin("move-cursor-page-down", editorMoveCursorPageDown);
+  registerBuiltin("editor-open-file", editorOpenFile);
+  registerBuiltin("editor-insert-char", editorPrintC);
+  registerBuiltin("add-package", addPackage);
+  registerBuiltin("buffer-find", bufferFind_L);
+  registerBuiltin("buffer-find-reverse", bufferFindReverse_L);
+  registerBuiltin("editor-read-char", editorReadChar_L);
+  registerBuiltin("add-prefix", editorPrefix);
+  registerBuiltin("editor-set-prefix", editorSetPrefix);
+  registerBuiltin("editor-insert-tab", l_editorInserTab);
+  registerBuiltin("editor-switch-next-buffer", editorSwitchNextBuffer);
+  registerBuiltin("editor-split-screen-vertical", l_editorSplitScreenVertical);
+  registerBuiltin("editor-switch-next-pane", editorSwitchNextPane);
+  registerBuiltin("editor-unify-panes", editorUnifiedPanes);
+  registerBuiltin("editor-paste", editorPaste);
+  registerBuiltin("editor-cut-end-line", editorCutEndLine);
+  registerBuiltin("editor-move-cursor-beg-buffer", editorMoveBegBuffer);
+  registerBuiltin("editor-move-cursor-end-buffer", editorMoveEndBuffer);
 }
 
-void initEditor() {
-  E.cursor_x = 0;
-  E.cursor_y = 0;
-  E.rx = 0;
-  E.row_offset = 0;
-  E.col_offset = 0;
-  E.numrows = 0;
-  E.row = NULL;
-  E.dirty = 0;
-  E.filename = NULL;
-  E.state = READ_ONLY;
-  E.status_msg[0] = '\0';
-  E.status_msg_time = 0;
-  if (getWindowSize(&E.screenrows, &E.screencols) == -1) {
-    die("getWindowSize");
-  }
-  E.screenrows -= 2;
+void initConfig() {
 
-  E.number_of_keybinds = 0;
-
-  
-  E.fd_init_file = fopen("config/init.lisp", "r");
   E.ctx = lisp_init();
+  E.ctx.p->err_port = fopen("log.err", "w");
   E.env = lisp_env(E.ctx);
   lisp_lib_load(E.ctx);
   // Init builtins lisp functions
@@ -67,7 +66,76 @@ void initEditor() {
     die("init failed");
   }
   lisp_eval(E.ctx_data, &E.ctx_error, E.ctx);
-  
+}
+
+void initTheme() {
+  E.constantes.THEME = (char *)lisp_string(
+      lisp_eval(lisp_read("THEME", &E.ctx_error, E.ctx), &E.ctx_error, E.ctx));
+  if (strcmp(E.constantes.THEME, "dark") == 0) {
+    E.theme.BACKGROUND_COLOR = ANSI_BG_RGB(40, 44, 52);
+    E.theme.COLOR_KEYWORD = ANSI_FG_RGB(198, 120, 221);
+    E.theme.COLOR_TYPE = ANSI_FG_RGB(97, 175, 239);
+    E.theme.COLOR_STRING = ANSI_FG_RGB(152, 195, 121);
+    E.theme.COLOR_COMMENT = ANSI_FG_RGB(92, 99, 112);
+    E.theme.COLOR_NUMBER = ANSI_FG_RGB(209, 154, 102);
+    E.theme.COLOR_DEFAULT = ANSI_FG_RGB(171, 178, 191);
+  } else {
+    E.theme.BACKGROUND_COLOR = ANSI_BG_RGB(250, 251, 252);
+    E.theme.COLOR_KEYWORD = ANSI_FG_RGB(166, 38, 164);
+    E.theme.COLOR_TYPE = ANSI_FG_RGB(4, 90, 180);
+    E.theme.COLOR_STRING = ANSI_FG_RGB(80, 161, 79);
+    E.theme.COLOR_COMMENT = ANSI_FG_RGB(152, 152, 152);
+    E.theme.COLOR_NUMBER = ANSI_FG_RGB(206, 102, 54);
+    E.theme.COLOR_DEFAULT = ANSI_FG_RGB(86, 89, 90);
+  }
+}
+
+void initEditor() {
+
+  if (getWindowSize(&E.screenrows, &E.screencols) == -1) {
+    die("getWindowSize");
+  }
+  appDebug("%d %d\n", E.screenrows, E.screencols);
+  E.screenrows -= 2;
+
+
+  // Init graphics variables
+  splitScreenInit();
+  EditorPane *active = splitScreenGetActivePane();
+  E.cursor_x = 0;
+  E.cursor_y = 0;
+
+  active->cursor_x = 0;
+  active->cursor_y = 0;
+  active->origin_x = 0;
+  active->origin_y = 0;
+  active->width = E.screencols;
+  active->height = E.screenrows;
+
+  E.init_file_path = (char *)calloc(256, sizeof(char));
+  strcat(E.init_file_path, getenv("HOME"));
+  strcat(E.init_file_path, "/.beluga/config/init.lisp");
+  appDebug("%s\n", E.init_file_path);
+  E.fd_init_file = fopen(E.init_file_path, "r");
+
+  // Status bar
+  E.status_msg = (char *)calloc(E.screencols, sizeof(char));
+  E.status_msg[0] = '\0';
+  E.status_msg_time = 0;
+
+  // Key binds
+  E.number_of_keybinds = 0;
+  E.number_of_prefix = 0;
+  // General prefix is 0 (no prefix)
+  E.prefix = (struct prefix_t *)malloc(sizeof(struct prefix_t));
+  E.prefix[0].prefix_id = 0;
+  strncpy(E.prefix[0].prefix_name, "no-prefix", 64);
+  E.prefix_state = 0;
+
+  initConfig();
+
+  initTheme();
+
   // To modify
 
   E.constantes.TAB_LENGTH =

src/input.c

@@ -1,26 +1,125 @@
 #include "../include/input.h"
+#include "../include/define.h"
 #include "../include/editor_op.h"
 #include "../include/output.h"
-#include "../include/define.h"
+#include "include/data.h"
+#include "include/buffer.h"
+#include "include/data.h"
+#include "include/split_screen.h"
 #include <ctype.h>
+#include <sys/stat.h>
+#include <dirent.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/stat.h>
 #include <unistd.h>
 
+#include "include/terminal.h"
+#include "include/utf8.h"
+
 extern struct editorConfig E;
 
 /**
- * \fn char * editorPrompt(struct editorConfig *E, char *prompt)
- * \brief Return user input in a prompt when enter is hit. */
+ * @file input.c
+ * @brief Input handling module for the Beluga text editor
+ * @details Manages user input processing, key bindings, cursor movement, and file path completion
+ */
 
-char *editorPrompt(char *prompt) {
-  size_t buf_size = 128;
+/**
+ * @brief Returns the first file completion match for the given path
+ * @details Searches the directory containing the given path prefix and returns
+ * the first file or directory entry that matches the filename prefix.
+ * Appends a trailing slash for directory entries.
+ * @param path The file path to complete (can be relative or absolute)
+ * @return Pointer to the completed file path (dynamically allocated), or NULL if:
+ *         - path ends with '/' (already a directory)
+ *         - no matching entries found
+ *         - directory cannot be opened
+ * @note Caller is responsible for freeing the returned string
+ * @note Uses static buffer internally; may return stale pointers across calls
+ */
+const char *fileCompletion(const char *path) {
+  DIR *dir;
+  struct dirent *entry;
+  char directory[256];
+  char predict[128];
+  const char *last_slash;
+  int predict_len = 0;
+  size_t dir_len;
+
+  // path is a directory
+  if (path[strlen(path) - 1] == '/') {
+    appDebug("[FILE COMP] is dir\n");
+    strncpy(directory, path, 256);
+  }
+
+  // Find dir name
+  last_slash = strrchr(path, '/');
+  if (last_slash) {
+    dir_len = last_slash - path + 1; // length of dir_path
+    strncpy(directory, path, dir_len);
+    predict_len = strlen(path) - dir_len;
+    strncpy(predict, last_slash + 1, predict_len);
+    directory[dir_len] = '\0';
+    predict[predict_len] = '\0';
+    appDebug("%s %s\n", directory, predict);
+  } else {
+    appDebug("[FILE COMP] dir not found\n");
+    return strdup(path);
+  }
+
+  dir = opendir(directory);
+  if (!dir)
+    return strdup(path);
+
+  while ((entry = readdir(dir)) != NULL) {
+    if (strncmp(entry->d_name, predict, predict_len) == 0) {
+      static char full_path[1024];
+      snprintf(full_path, sizeof(full_path), "%s%s", directory, entry->d_name);
+
+      struct stat st;
+      if (stat(full_path, &st) == 0 && S_ISDIR(st.st_mode)) {
+        strcat(full_path, "/"); // add slash for directories
+      }
+      closedir(dir);
+
+      return strdup(full_path);
+    }
+  }
+
+  // Cleanup when no more entries
+  closedir(dir);
+  dir = NULL;
+  free(entry);
+  appDebug("[FILE COMP] no entries\n");
+  return strdup(path);
+}
+
+/**
+ * @brief Displays an interactive prompt and returns user input
+ * @details Allows the user to enter text in a prompt with optional path completion
+ * via Tab key. Supports backspace, delete, and escape key handling. Dynamically
+ * allocates memory for the input buffer.
+ * @param prompt The prompt message format string (printf-style)
+ * @param placeHolder Initial text to display in the input buffer
+ * @param bPathMode If non-zero, enables Tab key file path completion
+ * @return Pointer to the user-entered text (dynamically allocated), or NULL if:
+ *         - User pressed ESC to cancel
+ *         - Input buffer is empty when Enter is pressed
+ * @note Caller is responsible for freeing the returned string
+ * @note Uses editorReadKey() for input and editorRefreshScreen() for display
+ */
+char *editorPrompt(char *prompt, char *placeHolder, char bPathMode) {
+  size_t buf_size = 256;
+  appDebug("[FILE COMP] %s %d\n", placeHolder, strlen(placeHolder));
   char *buf = malloc(buf_size);
   size_t buf_len = 0;
   int c = 0;
   buf[0] = '\0';
+  strcpy(buf, placeHolder);
+  buf_len = strlen(placeHolder);
 
   while (1) {
     editorSetStatusMessage(prompt, buf);
@@ -39,7 +138,27 @@ char *editorPrompt(char *prompt) {
         editorSetStatusMessage("");
         return buf;
       }
-    } else if (!iscntrl(c) && c < 128) {
+    } else if (bPathMode && c == '\t') {
+      char path[256];
+      char *pwd;
+      if (buf[0] != '/') {
+        pwd = getenv("PWD");
+        appDebug("%s\n", pwd);
+        memcpy(path, pwd, strlen(pwd));
+        path[strlen(pwd)] = '/';
+        strncat(path, buf, buf_len);
+      } else {
+        strcpy(path, buf);
+      }
+      memset(buf, 0, 256);
+      buf_len = 0;
+      char * buf_complete = (char *) fileCompletion(path);
+      strcpy(buf, buf_complete);
+      free(buf_complete);
+      buf_len = strlen(buf);
+      buf[buf_len] = '\0';
+
+    } else if (!iscntrl(c) && c < 256) {
       if (buf_len == buf_size - 1) {
         buf_size *= 2;
         buf = realloc(buf, buf_size);
@@ -50,134 +169,55 @@ char *editorPrompt(char *prompt) {
   }
 }
 
-char *key_to_string(int key) {
-  static char key_str[32];
-
-  char tmp[10];
-  sprintf(tmp, "%d", key);
 
 
-  // First test enter key
-
-  if (key == '\r') {
-    strcpy(key_str, "ENTER");
-  } else if (key >= 1 && key <= 26) { // CTRL keys
-    snprintf(key_str, sizeof(key_str), "CTRL-%c", 'a' + key - 1);
-  } else {
-    switch (key) {
-    case ARROW_UP:
-      strcpy(key_str, "ARROW-UP");
-      break;
-    case ARROW_DOWN:
-      strcpy(key_str, "ARROW-DOWN");
-      break;
-    case ARROW_LEFT:
-      strcpy(key_str, "ARROW-LEFT");
-      break;
-    case ARROW_RIGHT:
-      strcpy(key_str, "ARROW-RIGHT");
-      break;
-    case PAGE_UP:
-      strcpy(key_str, "PAGE-UP");
-      fprintf(stderr, "pagr up\n");
-      break;
-    case PAGE_DOWN:
-      strcpy(key_str, "PAGE-DOWN");
-      break;
-    case DEL_KEY:
-      fprintf(stderr, "delete key\n");
-      strcpy(key_str, "DEL");
-      
-      break;
-    case BACKSPACE:
-      strcpy(key_str, "BACKSPACE");
-      break;
-    case '\r':
-      strcpy(key_str, "ENTER");
-      break;
-    case '\x1b':
-      strcpy(key_str, "ESCAPE");
-      break;
-    case BEG_LINE:
-      strcpy(key_str, "HOME");
-      break;
-    case END_LINE:
-      strcpy(key_str, "END");
-      break;
-    default:
-      // For regular characters
-      if (isprint(key)) {
-        snprintf(key_str, sizeof(key_str), "%c", key);
-      } else {
-        snprintf(key_str, sizeof(key_str), "KEY-%d", key);
-      }
-    }
-  }
-  return key_str;
-}
-
-
-void editorMoveCursor(int key) {
-  erow *row = (E.cursor_y >= E.numrows) ? NULL : &E.row[E.cursor_y];
-  int row_len;
-  switch (key) {
-  case ARROW_RIGHT:
-    if (row && E.cursor_x < row->size) {
-      ++E.cursor_x;
-    } else if (row && E.cursor_x == row->size) {
-      E.cursor_y++;
-      E.cursor_x = 0;
-    }
-    break;
-  case ARROW_DOWN:
-    if (E.cursor_y < E.numrows) {
-      ++E.cursor_y;
-    }
-    break;
-  case ARROW_UP:
-    if (E.cursor_y != 0) {
-      --E.cursor_y;
-    }
-    break;
-  case ARROW_LEFT:
-    if (E.cursor_x != 0) {
-      --E.cursor_x;
-    } else if (E.cursor_y > 0) {
-      --E.cursor_y;
-      E.cursor_x = E.row[E.cursor_y].size;
-    }
-    break;
-  }
-
-  row = (E.cursor_y >= E.numrows) ? NULL : &E.row[E.cursor_y];
-  row_len = row ? row->size : 0;
-  if (E.cursor_x > row_len) {
-    E.cursor_x = row_len;
-  }
-}
-
+/**
+ * @brief Executes the command bound to a key sequence
+ * @details Searches the keybinding table for a matching key sequence and
+ * prefix state, then evaluates the associated Lisp command.
+ * @param key_sequence The string representation of the key sequence
+ * @return 1 if a matching keybinding was found and executed, 0 otherwise
+ * @note Updates global editor state E (prefix_state)
+ * @note Uses Lisp interpreter to evaluate bound commands
+ */
 int executeKeyBind(char *key_sequence) {
   int i;
+  int previous_state = 0;
+  appDebug("pressed %s\n", key_sequence);
   for (i = 0; i < E.number_of_keybinds; ++i) {
     if (!strcmp(key_sequence, E.key_binds[i].key_sequence)) {
-  
-        fprintf(stderr, "lisp function %s\n", key_sequence);
-        // It's a symbol, create a function call
-        lisp_eval(lisp_cons(E.key_binds[i].command, lisp_null(), E.ctx),
-                  &E.ctx_error, E.ctx);
-        return 1;
+      if (E.prefix_state != E.key_binds[i].prefix_id) {
+        continue;
+      }
+      previous_state = E.prefix_state;
+      // It's a symbol, create a function call
+      lisp_eval(lisp_cons(E.key_binds[i].command, lisp_null(), E.ctx),
+                &E.ctx_error, E.ctx);
+      if (E.prefix_state == previous_state)
+        E.prefix_state = 0;
+      return 1;
     }
   }
   return 0;
 }
 
+/**
+ * @brief Processes a single keypress from the user
+ * @details Reads a key, checks if it matches any registered keybinding,
+ * and either executes the bound command or inserts the character. Resets
+ * the quit buffer counter on successful key processing.
+ * @note Updates global editor state E
+ * @note Calls editorReadKey() to get input and editorInsertChar() for unbound keys
+ */
 void editorProcessKeypress() {
   int c = editorReadKey();
+  char key_sequence[8];
 
-  if (executeKeyBind(key_to_string(c))) {
+  if (executeKeyBind(keyToString(c))) {
     return;
   }
-  editorInsertChar(c);
+  int seq_len = utf8Encode(c, key_sequence);
+  appDebug("key seq : %s\n", key_sequence);
+  bufferInsertBytes(key_sequence, seq_len);
   E.quit_times_buffer = E.constantes.QUIT_TIMES;
-
 }

src/output.c

@@ -1,137 +1,375 @@
+/**
+ * @file output.c
+ * @brief Screen rendering and output module for the Beluga text editor
+ * @details Handles all screen updates, cursor positioning, status bar
+ * rendering, and display synchronization using ANSI escape sequences
+ */
+
 #include "../include/output.h"
-#include <stdarg.h>
+#include "../include/append_buffer.h"
+#include "../include/buffer.h"
+#include "../include/editor_op.h"
+#include "../include/data.h"
+#include "../include/define.h"
+#include "../include/row_op.h"
+#include "../include/split_screen.h"
+#include "../include/syntax_highlighter.h"
+#include "../include/terminal.h"
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <time.h>
 
 extern struct editorConfig E;
 
-void editorDrawRows(struct abuf *ab) {
-  int y;
-  char welcome[80];
-  int welcome_len;
-  int padding;
-  int len;
-  int file_row;
-  for (y = 0; y < E.screenrows; ++y) {
-    file_row = y + E.row_offset;
-    if (file_row >= E.numrows) {
-      if (E.numrows == 0 && y == E.screenrows / 3) {
-        welcome_len =
-            snprintf(welcome, sizeof(welcome),
-                     "Beluga text editor -- version %s", BELUGA_VERSION);
-        if (welcome_len > E.screencols) {
-          welcome_len = E.screencols;
+/**
+ * @brief Renders a single pane with its buffer content
+ */
+static void editorDrawPane(struct abuf* ab, EditorPane* pane)
+{
+    int file_row;
+    char pos_buf[32];
+    int pos_len;
+    int byte_len_to_print;
+    int bytes_to_print;
+    char* highlighted;
+
+    if (pane == NULL || pane->buffer_id < 0)
+        return;
+
+    const struct buffer_t* buf = bufferFindById(pane->buffer_id);
+    if (buf == NULL)
+        return;
+
+    // Draw all pane
+    for (int y = 0; y < pane->height; y++)
+    {
+        file_row = y + pane->y_offset;
+
+        // Set cursor at start of pane row
+        pos_len = snprintf(pos_buf, sizeof(pos_buf), "\x1b[%d;%dH",
+                           pane->origin_y + y + 1, pane->origin_x + 1);
+        abAppend(ab, pos_buf, pos_len);
+
+        // Apply background color (6 bytes for RGB format)
+        abAppend(ab, E.theme.BACKGROUND_COLOR, (int) strlen(E.theme.BACKGROUND_COLOR));
+
+
+        // pane line is out of buffer
+        if (file_row >= buf->numrows)
+        {
+            // Empty line - show tilde
+
+            abAppend(ab, "~", 1);
+            for (int i = 0;
+                 i < pane->width - 1;
+                 ++i)
+            {
+                abAppend(ab, " ", 1);
+            }
         }
-        padding = (E.screencols - welcome_len) / 2;
-        if (padding) {
-          abAppend(ab, "~", 1);
-          --padding;
+        else
+        {
+
+
+            if (buf->filename[strlen(buf->filename) - 1] == 'c' || buf->filename[strlen(buf->filename) - 1] == 'h')
+            {
+                // Render line with syntax highlighting, constrain to pane width
+                highlighted = highlight_line(
+                    &buf->row[file_row].chars[pane->x_offset], &byte_len_to_print);
+
+                // Print only up to pane width
+                abAppend(ab, highlighted, byte_len_to_print);
+                free(highlighted);
+            }
+            else
+            {
+                // Render basic line
+                bytes_to_print =
+                    buf->row[file_row].size - pane->x_offset < pane->width
+                        ? buf->row[file_row].size - pane->x_offset
+                        : pane->width;
+                abAppend(ab, &buf->row[file_row].chars[pane->x_offset], bytes_to_print);
+            }
+            // Fill remaining space with background color to pane width
+            for (int i = 0;
+                 i < pane->width - editorRowCharCount(&buf->row[file_row], pane->width) + pane->x_offset;
+                 ++i)
+            {
+                abAppend(ab, " ", 1);
+            }
         }
-        while (padding--) {
-          abAppend(ab, " ", 1);
+    }
+}
+
+/**
+ * @brief Renders all panes based on current split configuration
+ */
+static void editorDrawAllPanes(struct abuf* ab)
+{
+    const ScreenLayout* layout = splitScreenGetLayout();
+
+    if (layout->num_panes == 1)
+    {
+        // Single pane fullscreen
+        editorDrawPane(ab, &layout->panes[0]);
+    }
+    else if (layout->num_panes == 2)
+    {
+        // Draw both panes
+        for (int i = 0; i < 2; i++)
+        {
+            editorDrawPane(ab, &layout->panes[i]);
+
+            // Draw pane border/divider if not the last pane
+            if (layout->mode == SPLIT_VERTICAL && i == 0)
+            {
+                // Draw vertical divider
+                int divider_col = layout->panes[0].width;
+                for (int y = 0; y < layout->panes[0].height; y++)
+                {
+                    char pos_buf[32];
+                    snprintf(pos_buf, sizeof(pos_buf), "\x1b[%d;%dH", y + 1, divider_col);
+                    abAppend(ab, pos_buf, (int) strlen(pos_buf));
+                    abAppend(ab, "\x1b[1m|\x1b[0m", 9); // Bold pipe divider
+                }
+            }
+            else if (layout->mode == SPLIT_HORIZONTAL && i == 0)
+            {
+                // Draw horizontal divider
+                int divider_row = layout->panes[0].height;
+                char pos_buf[32];
+                snprintf(pos_buf, sizeof(pos_buf), "\x1b[%d;%dH", divider_row + 1, 1);
+                abAppend(ab, pos_buf, (int) strlen(pos_buf));
+                for (int x = 0; x < E.screencols; x++)
+                {
+                    abAppend(ab, "\x1b[1m-\x1b[0m", 9); // Bold dash divider
+                }
+            }
         }
-        abAppend(ab, welcome, welcome_len);
-      } else {
-        abAppend(ab, "~", 1);
-      }
-    } else {
-      len = E.row[file_row].rsize - E.col_offset;
-      if (len < 0)
-        len = 0;
-      if (len > E.screencols)
+    }
+}
+
+/**
+ * @brief Updates scroll offsets to keep cursor visible on screen
+ * @details Adjusts E.row_offset and E.col_offset to ensure the cursor remains
+ * within the visible viewport. Also updates E.rx (rendered x-coordinate).
+ * @note Updates global editor state E
+ * @see editorRowCxToRx()
+ */
+void editorScroll()
+{
+    EditorPane* active = splitScreenGetActivePane();
+    struct buffer_t* buf = bufferFindById(active->buffer_id);
+    int rel_x, rel_y;
+
+    // compute relative coordinates
+    rel_x = editorRowCharCount(&buf->row[buf->y], buf->x);
+    appDebug("counting %d\n", rel_x);
+    rel_y = buf->y;
+
+    appDebug("%d %d / %d %d\n", active->cursor_x, active->x_offset,
+             active->cursor_y, active->y_offset);
+
+    while (rel_x != active->cursor_x + active->x_offset ||
+        rel_y != active->cursor_y + active->y_offset)
+    {
+        if (rel_x < active->cursor_x + active->x_offset)
+        {
+            // LEFT
+            if (active->cursor_x == 0 && active->x_offset)
+            {
+                active->x_offset--;
+            } else
+            {
+                active->cursor_x--;
+            }
+        } else
+        {
+            // RIGHT
+            if (rel_x > active->cursor_x + active->x_offset)
+            {
+                if (active->cursor_x == active->width - 1)
+                {
+                    active->x_offset++;
+                } else
+                {
+                    active->cursor_x++;
+                }
+            }
+        }
+
+        if (rel_y < active->cursor_y + active->y_offset)
+        {
+            if (active->cursor_y == 0 && active->y_offset)
+            {
+                active->y_offset--;
+            } else
+            {
+                active->cursor_y--;
+            }
+        }
+
+        if (rel_y > active->cursor_y + active->y_offset)
+        {
+            if (active->cursor_y == active->height - 1)
+            {
+                active->y_offset++;
+            } else
+            {
+                active->cursor_y++;
+            }
+        }
+
+    }
+}
+
+char * basename(char *path)
+{
+    int len = (int) strlen(path);
+
+
+    for(int i=len-1; i>0; i--)
+    {
+        if(path[i]=='/' )
+        {
+            path = path+i+1;
+            break;
+        }
+    }
+    return path;
+}
+
+/**
+ * @brief Renders the status bar at the bottom of the screen
+ * @details Displays filename, line count, dirty flag, and current cursor
+ * position in an inverted color bar. Right-aligns the cursor position
+ * indicator.
+ * @param ab Pointer to append buffer structure for accumulating output
+ * @note Uses ANSI escape codes for color inversion
+ */
+void editorDrawStatusBar(struct abuf* ab)
+{
+    // TO MODIFY
+    int len, render_len;
+    char status[E.screencols], render_status[E.screencols * 4];
+    EditorPane* active = splitScreenGetActivePane();
+    struct buffer_t* buf = bufferFindById(active->buffer_id);
+
+    abAppend(ab, "\x1b[7m", 4); // inverting colors
+
+    const char* mode_str = "";
+    ScreenLayout* layout = splitScreenGetLayout();
+    if (layout->mode == SPLIT_VERTICAL)
+        mode_str = " [V-SPLIT]";
+    else if (layout->mode == SPLIT_HORIZONTAL)
+        mode_str = " [H-SPLIT]";
+
+    // Build buffer status showing all buffers with dirty indicators
+    char buf_status[1024] = "";
+    int offset = 0;
+    for (int i = 0; i < E.number_of_buffer; i++)
+    {
+        struct buffer_t* b = &E.buffers[i];
+        char marker = (b->buffer_id == active->buffer_id) ? '>' : ' ';
+        char dirty_marker = b->dirty ? '*' : ' ';
+        offset += snprintf(&buf_status[offset], sizeof(buf_status) - offset,
+                           "%c%d:%s%c ", marker, b->buffer_id,
+                           b->filename ? basename(b->filename) : "[No Name]", dirty_marker);
+    }
+
+    len = snprintf(status, sizeof(status), "%s%s", buf_status, mode_str);
+
+    render_len = snprintf(render_status, sizeof(render_status), "%d/%d",
+                          active->cursor_y + 1, buf->numrows);
+
+    if (len > E.screencols)
+    {
         len = E.screencols;
-      abAppend(ab, &E.row[file_row].render[E.col_offset], len);
     }
-    abAppend(ab, ERASE_END_LINE, 3);
+
+    abAppend(ab, status, len);
+    while (len < E.screencols)
+    {
+        if (E.screencols - len == render_len + 1)
+        {
+            abAppend(ab, render_status, render_len);
+            break;
+        }
+        else
+        {
+            abAppend(ab, " ", 1);
+            ++len;
+        }
+    }
+
+    abAppend(ab, "\x1b[m", 3); // normal text mode
     abAppend(ab, "\r\n", 2);
-  }
 }
 
-void editorScroll() {
-  E.rx = E.cursor_x;
-  if (E.cursor_y < E.numrows) {
-    E.rx = editorRowCxToRx(&E.row[E.cursor_y], E.cursor_x);
-  }
-
-  if (E.cursor_y < E.row_offset) {
-    E.row_offset = E.cursor_y;
-  }
-  if (E.cursor_y >= E.row_offset + E.screenrows) {
-    E.row_offset = E.cursor_y - E.screenrows + 1;
-  }
-  if (E.rx < E.col_offset) {
-    E.col_offset = E.rx;
-  }
-  if (E.rx >= E.col_offset + E.screencols) {
-    E.col_offset = E.rx - E.screencols + 1;
-  }
-}
-
-void editorDrawStatusBar(struct abuf *ab) {
-  int len, render_len;
-  char status[80], render_status[80];
-
-  abAppend(ab, "\x1b[7m", 4); // inverting colors
-  len = snprintf(status, sizeof(status), "%.20s - %d lines%s",
-                 E.filename ? E.filename : "[No Name]", E.numrows,
-                 E.dirty ? "*" : "");
-  render_len = snprintf(render_status, sizeof(render_status), "%d/%d",
-                        E.cursor_y + 1, E.numrows);
-  if (len > E.screencols) {
-    len = E.screencols;
-  }
-  abAppend(ab, status, len);
-  while (len < E.screencols) {
-    if (E.screencols - len == render_len) {
-      abAppend(ab, render_status, render_len);
-      break;
-    } else {
-      abAppend(ab, " ", 1);
-      ++len;
+/**
+ * @brief Renders the message bar below the status bar
+ * @details Displays temporary status messages for a limited time (5 seconds).
+ * Only displays message if within time window and within screen width.
+ * @param ab Pointer to append buffer structure for accumulating output
+ * @note Messages are set by editorSetStatusMessage()
+ */
+void editorDrawMessageBar(struct abuf* ab)
+{
+    int msg_len = (int) strlen(E.status_msg);
+    abAppend(ab, ERASE_END_LINE, 3);
+    if (msg_len > E.screencols)
+    {
+        msg_len = E.screencols;
+    }
+    if (msg_len && time(NULL) - E.status_msg_time < 5)
+    {
+        abAppend(ab, E.status_msg, msg_len);
     }
-  }
-  abAppend(ab, "\x1b[m", 3); // normal text mode
-  abAppend(ab, "\r\n", 2);
 }
 
-void editorDrawMessageBar(struct abuf *ab) {
-  int msg_len = strlen(E.status_msg);
-  abAppend(ab, ERASE_END_LINE, 3);
-  if (msg_len > E.screencols) {
-    msg_len = E.screencols;
-  }
-  if (msg_len && time(NULL) - E.status_msg_time < 5) {
-    abAppend(ab, E.status_msg, msg_len);
-  }
-}
-
-void editorRefreshScreen() {
-  editorScroll();
-  struct abuf ab = ABUF_INIT;
-  char buf[32];
-
-  abAppend(&ab, HIDE_CURSOR, 6);
-  abAppend(&ab, CURSOR_TOP_LEFT, 3);
-
-  editorDrawRows(&ab);
-  editorDrawStatusBar(&ab);
-  editorDrawMessageBar(&ab);
-
-  snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (E.cursor_y - E.row_offset) + 1,
-           (E.rx - E.col_offset) + 1);
-  abAppend(&ab, buf, strlen(buf));
-
-  abAppend(&ab, SHOW_CURSOR, 6);
-
-  write(STDOUT_FILENO, ab.b, ab.len);
-  abFree(&ab);
-}
-
-void editorSetStatusMessage(const char *fmt, ...) {
-  va_list ap;
-  va_start(ap, fmt);
-  vsnprintf(E.status_msg, sizeof(E.status_msg), fmt, ap);
-  va_end(ap);
-  E.status_msg_time = time(NULL);
+
+/**
+ * @brief Performs complete screen refresh and buffer synchronization
+ * @details Clears screen, redraws all visible content (rows, status bar,
+ * message bar), positions cursor, and writes accumulated buffer to stdout. This
+ * is the main rendering function called each frame.
+ * @note Updates global editor state E (via editorScroll())
+ * @see editorDrawRows()
+ * @see editorDrawStatusBar()
+ * @see editorDrawMessageBar()
+ */
+
+void editorRefreshScreen()
+{
+    struct abuf ab = ABUF_INIT;
+    char buf[32];
+
+    abAppend(&ab, HIDE_CURSOR, 6);
+    abAppend(&ab, CURSOR_TOP_LEFT, 3);
+    abAppend(&ab, E.theme.BACKGROUND_COLOR,
+             (int) strlen(E.theme.BACKGROUND_COLOR)); // RGB background is 12 bytes
+
+    // Draw all panes
+    editorScroll();
+    editorDrawAllPanes(&ab);
+
+    // Draw status bar and message bar
+    editorDrawStatusBar(&ab);
+    editorDrawMessageBar(&ab);
+    // editorDrawContextBuffer(&ab);
+
+    // Position cursor in active pane
+    EditorPane* active = splitScreenGetActivePane();
+    if (active != NULL)
+    {
+        snprintf(buf, sizeof(buf), "\x1b[%d;%dH",
+                 active->cursor_y + active->origin_y + 1,
+                 active->cursor_x + active->origin_x + 1);
+        abAppend(&ab, buf, (int) strlen(buf));
+    }
+
+    abAppend(&ab, SHOW_CURSOR, 6);
+    write(STDOUT_FILENO, ab.b, ab.len);
+    abFree(&ab);
 }

src/row_op.c

@@ -1,4 +1,6 @@
 #include "../include/row_op.h"
+#include "../include/data.h"
+#include "../include/utf8.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -6,134 +8,5 @@
 
 extern struct editorConfig E;
 
-int editorRowCxToRx(erow *row, int cursor_x) {
-  int render_x = 0;
-  int i;
-  for (i = 0; i < cursor_x; ++i) {
-    if (row->chars[i] == '\t') {
-      render_x += (E.constantes.TAB_LENGTH - 1) - (render_x % E.constantes.TAB_LENGTH);
-    }
-    render_x++;
-  }
-  return render_x;
-}
 
-/**
- * \fn editorUpdateRow(erow *row)
- * \brief Copy content of \p row in \p row->render.
- *  */
 
-void editorUpdateRow(erow *row) {
-  int i, i_render;
-  int tabs = 0;
-
-  // counting number of tabs
-
-  for (i = 0; i < row->size; ++i) {
-    tabs +=
-        (row->chars[i] == '\t'); /**< increment tabs of 1 if chars[i] is one. */
-  }
-
-  free(row->render);
-  row->render = malloc(row->size + tabs * (E.constantes.TAB_LENGTH - 1) +
-                       1); /**< Tabs needs E.constantes.TAB_LENGTH chars so E.constantes.TAB_LENGTH - 1
-                              more than the first already counted. */
-
-  // end of counting
-  i_render = 0;
-  for (i = 0; i < row->size; ++i) {
-    if (row->chars[i] == '\t') {
-      row->render[i_render++] = ' ';
-      while (i_render % E.constantes.TAB_LENGTH) {
-        row->render[i_render++] =
-            ' '; /**< Addind the right amount of spaces for tabs */
-      }
-    } else {
-      row->render[i_render++] = row->chars[i];
-    }
-  }
-  row->render[i_render] = '\0'; // Don't forget the end of string character.
-  row->rsize = i_render;
-}
-
-void editorInsertRow(int at, char *s, size_t len) {
-  if (at < 0 || at > E.numrows) {
-    
-    return;
-  }
-  erow *tmp = (erow *)realloc(E.row, sizeof(erow) * (E.numrows + 1));
-  if (!tmp) {
-    return;
-  }
-  E.row = tmp;
-  memmove(&E.row[at + 1], &E.row[at], sizeof(erow) * (E.numrows - at));
-
-  E.row[at].size = len;
-  E.row[at].chars = malloc(len + 1);
-  memcpy(E.row[at].chars, s, len);
-  E.row[at].chars[len] = '\0';
-
-  E.row[at].rsize = 0;
-  E.row[at].render = NULL;
-  editorUpdateRow(&E.row[at]);
-
-  ++E.numrows;
-  ++E.dirty;
-}
-
-void editorFreeRow(erow *row) {
-  free(row->render);
-  free(row->chars);
-}
-
-void editorDelRow(int at) {
-  if (at < 0 || at >= E.numrows) {
-    return;
-  }
-  editorFreeRow(&E.row[at]);
-  memmove(&E.row[at], &E.row[at + 1], sizeof(erow) * (E.numrows - at - 1));
-  --E.numrows;
-  ++E.dirty;
-}
-
-/**
- * \fn editorRowInsertChar(erow *row, int at, int c)
- * \param at Index of where we want to insert the char */
-
-void editorRowInsertChar(erow *row, int at, int c) {
-  if (E.state == READ_ONLY)
-    return;
-  if (at < 0 || at > row->size) {
-    at = row->size;
-  }
-  row->chars = realloc(row->chars, row->size + 2);
-  memmove(&row->chars[at + 1], &row->chars[at], row->size - at + 1);
-  ++row->size;
-  row->chars[at] = c;
-  editorUpdateRow(row);
-  ++E.dirty;
-}
-
-void editorRowAppendString(erow *row, char *s, size_t len) {
-  row->chars = realloc(row->chars, row->size + len + 1);
-  memcpy(&row->chars[row->size], s, len);
-  row->size += len;
-  row->chars[row->size] = '\0';
-  editorUpdateRow(row);
-  ++E.dirty;
-}
-
-/**
- * \fn editorRowDelChar(struct editorConfig *E, erow *erow, int at)
- * \brief Delete the a char at the chosen position on the given row
- * \param at Index of the char to delete
- * \param row Row on operation is made */
-void editorRowDelchar(erow *row, int at) {
-  if (at < 0 || at >= row->size) {
-    return;
-  }
-  memmove(&row->chars[at], &row->chars[at + 1], row->size - at);
-  --row->size;
-  editorUpdateRow(row);
-  ++E.dirty;
-}

src/split_screen.c

@@ -0,0 +1,218 @@
+/**
+ * @file split_screen.c
+ * @brief Split screen implementation
+ */
+
+#include "../include/split_screen.h"
+#include "../include/buffer.h"
+#include "../include/editor_op.h"
+#include <stdlib.h>
+#include <string.h>
+
+extern struct editorConfig E;
+
+/**
+ * @brief Initializes split screen system with single fullscreen pane
+ */
+void splitScreenInit(void) {
+    E.layout.mode = SPLIT_NONE;
+    E.layout.num_panes = 1;
+    E.layout.active_pane = 0;
+
+    E.layout.panes = malloc(sizeof(EditorPane) * 2);
+
+    // Initialize single fullscreen pane
+    E.layout.panes[0].buffer_id = -1; // No buffer for now
+    E.layout.panes[0].origin_y = 0;
+    E.layout.panes[0].origin_x = 0;
+    E.layout.panes[0].height = E.screenrows - 2;  // Leave room for status bar
+    E.layout.panes[0].width = E.screencols;
+    E.layout.panes[0].cursor_x = 0;
+    E.layout.panes[0].cursor_y = 0;
+    E.layout.panes[0].y_offset = 0;
+    E.layout.panes[0].x_offset = 0;
+    E.layout.panes[0].is_active = 1;
+}
+
+/**
+ * @brief Splits screen vertically (left-right)
+ * @param buffer_id_left Buffer ID for left pane
+ * @param buffer_id_right Buffer ID for right pane
+ * @return 0 on success, -1 on failure
+ */
+int splitScreenVertical(int buffer_id_left, int buffer_id_right) {
+    // Verify both buffers exist
+    if (bufferFindById(buffer_id_left) == NULL ||
+        bufferFindById(buffer_id_right) == NULL) {
+        editorSetStatusMessage("Error: invalid buffer IDs");
+        return -1;
+    }
+
+    // Reallocate panes array
+    E.layout.panes = realloc(E.layout.panes, sizeof(EditorPane) * 2);
+    E.layout.mode = SPLIT_VERTICAL;
+    E.layout.num_panes = 2;
+    E.layout.active_pane = 0;
+
+    int half_width = E.screencols / 2;
+    int pane_height = E.screenrows;  // Leave room for status bar
+
+    // Left pane
+    E.layout.panes[0].buffer_id = buffer_id_left;
+    E.layout.panes[0].origin_y = 0;
+    E.layout.panes[0].origin_x = 0;
+    E.layout.panes[0].height = pane_height;
+    E.layout.panes[0].width = half_width;
+    E.layout.panes[0].cursor_x = 0;
+    E.layout.panes[0].cursor_y = 0;
+    E.layout.panes[0].y_offset = 0;
+    E.layout.panes[0].x_offset = 0;
+    E.layout.panes[0].is_active = 1;
+
+    // Right pane
+    E.layout.panes[1].buffer_id = buffer_id_right;
+    E.layout.panes[1].origin_y = 0;
+    E.layout.panes[1].origin_x = half_width;
+    E.layout.panes[1].height = pane_height;
+    E.layout.panes[1].width = E.screencols - half_width;
+    E.layout.panes[1].cursor_x = 0;
+    E.layout.panes[1].cursor_y = 0;
+    E.layout.panes[1].y_offset = 0;
+    E.layout.panes[1].x_offset = 0;
+    E.layout.panes[1].is_active = 0;
+
+    editorSetStatusMessage("Vertical split: %d | %d", buffer_id_left, buffer_id_right);
+    return 0;
+}
+
+/**
+ * @brief Splits screen horizontally (top-bottom)
+ * @param buffer_id_top Buffer ID for top pane
+ * @param buffer_id_bottom Buffer ID for bottom pane
+ * @return 0 on success, -1 on failure
+ */
+int splitScreenHorizontal(int buffer_id_top, int buffer_id_bottom) {
+    // Verify both buffers exist
+    if (bufferFindById(buffer_id_top) == NULL ||
+        bufferFindById(buffer_id_bottom) == NULL) {
+        editorSetStatusMessage("Error: invalid buffer IDs");
+        return -1;
+    }
+
+    // Reallocate panes array
+    E.layout.panes = realloc(E.layout.panes, sizeof(EditorPane) * 2);
+    E.layout.mode = SPLIT_HORIZONTAL;
+    E.layout.num_panes = 2;
+    E.layout.active_pane = 0;
+
+    int half_height = (E.screenrows - 2) / 2;  // Account for status bar
+
+    // Top pane
+    E.layout.panes[0].buffer_id = buffer_id_top;
+    E.layout.panes[0].origin_y = 0;
+    E.layout.panes[0].origin_x = 0;
+    E.layout.panes[0].height = half_height;
+    E.layout.panes[0].width = E.screencols;
+    E.layout.panes[0].cursor_x = 0;
+    E.layout.panes[0].cursor_y = 0;
+    E.layout.panes[0].y_offset = 0;
+    E.layout.panes[0].x_offset = 0;
+    E.layout.panes[0].is_active = 1;
+
+    // Bottom pane
+    E.layout.panes[1].buffer_id = buffer_id_bottom;
+    E.layout.panes[1].origin_y = half_height;
+    E.layout.panes[1].origin_x = 0;
+    E.layout.panes[1].height = E.screenrows - 2 - half_height;
+    E.layout.panes[1].width = E.screencols;
+    E.layout.panes[1].cursor_x = 0;
+    E.layout.panes[1].cursor_y = 0;
+    E.layout.panes[1].x_offset = 0;
+    E.layout.panes[1].y_offset = 0;
+    E.layout.panes[1].is_active = 0;
+
+    editorSetStatusMessage("Horizontal split: %d / %d", buffer_id_top, buffer_id_bottom);
+    return 0;
+}
+
+/**
+ * @brief Returns to single buffer fullscreen
+ */
+void splitScreenUnify(void) {
+    E.layout.mode = SPLIT_NONE;
+    E.layout.num_panes = 1;
+    E.layout.active_pane = 0;
+
+    E.layout.panes[0].origin_x = 0;
+    E.layout.panes[0].origin_y = 0;
+    E.layout.panes[0].height = E.screenrows;
+    E.layout.panes[0].width = E.screencols;
+    E.layout.panes[0].is_active = 1;
+
+    editorSetStatusMessage("Unified view");
+}
+
+/**
+ * @brief Switches active pane (focus moves between splits)
+ * @return 0 on success, -1 on failure
+ */
+int splitScreenSwitchPane(void) {
+    if (E.layout.num_panes < 2) {
+        editorSetStatusMessage("No split to switch");
+        return -1;
+    }
+
+    // Deactivate current pane
+    E.layout.panes[E.layout.active_pane].is_active = 0;
+
+    // Move to next pane
+    E.layout.active_pane = (E.layout.active_pane + 1) % E.layout.num_panes;
+
+    // Activate new pane
+    E.layout.panes[E.layout.active_pane].is_active = 1;
+
+    editorSetStatusMessage("Switched to pane %d (buffer %d)",
+                          E.layout.active_pane,
+                          E.layout.panes[E.layout.active_pane].buffer_id);
+    return 0;
+}
+
+/**
+ * @brief Updates the active pane's buffer
+ * @param buffer_id New buffer ID for active pane
+ * @return 0 on success, -1 on failure
+ */
+int splitScreenSetPaneBuffer(int buffer_id) {
+    if (bufferFindById(buffer_id) == NULL) {
+        editorSetStatusMessage("Error: invalid buffer ID");
+        return -1;
+    }
+
+    EditorPane *active = &E.layout.panes[E.layout.active_pane];
+    active->buffer_id = buffer_id;
+    active->cursor_x = 0;
+    active->cursor_y = 0;
+    active->origin_x = 0;
+    active->origin_y = 0;
+
+    editorSetStatusMessage("Pane %d now showing buffer %d",
+                          E.layout.active_pane, buffer_id);
+    return 0;
+}
+
+/**
+ * @brief Gets current screen layout
+ * @return Pointer to current ScreenLayout
+ */
+ScreenLayout *splitScreenGetLayout(void) {
+    return &E.layout;
+}
+
+/**
+ * @brief Gets active pane
+ * @return Pointer to active EditorPane
+ */
+EditorPane *splitScreenGetActivePane(void) {
+    if (E.layout.num_panes == 0) return NULL;
+    return &E.layout.panes[E.layout.active_pane];
+}

src/syntax_highlighter.c

@@ -0,0 +1,248 @@
+#include "../include/syntax_highlighter.h"
+#include "../include/data.h"
+#include "../include/utf8.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+extern struct editorConfig E;
+
+const char *c_keywords[] = {
+    "if",     "else",     "while",    "for",     "do",       "switch",
+    "case",   "break",    "#include", "#define", "#if", "#endif", "#ifndef", "continue", "return",
+    "goto",   "struct",   "union",    "enum",    "typedef",  "static",
+    "extern", "const",    "volatile", "sizeof",  "auto",     "register",
+    "inline", "restrict", NULL};
+
+// C types
+const char *c_types[] = {"int",    "char", "float", "double",
+                         "void",   "long", "short", "unsigned",
+                         "signed", "bool", NULL};
+
+// Returns the byte length of the UTF-8 character starting at s.
+// Never returns 0 for a non-NUL byte, so callers won't infinite-loop.
+static int utf8_char_len(const char *s)
+{
+    unsigned char c = (unsigned char)*s;
+    if (c == 0)              return 0;
+    if (c < 0x80)            return 1;
+    if ((c & 0xE0) == 0xC0)  return 2;
+    if ((c & 0xF0) == 0xE0)  return 3;
+    if ((c & 0xF8) == 0xF0)  return 4;
+    return 1; // continuation byte or invalid — advance 1 to avoid infinite loop
+}
+
+// Copy one full UTF-8 character from src+i into dst+pos, advance both indices.
+static void copy_utf8_char(char *dst, int *dst_pos, const char *src, int *src_pos)
+{
+    int len = utf8_char_len(&src[*src_pos]);
+    for (int b = 0; b < len; b++)
+        dst[(*dst_pos)++] = src[(*src_pos)++];
+}
+
+// Check if character is alphanumeric or underscore
+int is_word_char(const char *s)
+{
+    uint32_t cp = utf8Decode(&s);
+
+    if ((cp >= 'a' && cp <= 'z') || (cp >= 'A' && cp <= 'Z') ||
+        (cp >= '0' && cp <= '9') || cp == '_' || cp == '#')
+        return 1;
+
+    if (cp == 0xFFFD) return 0;
+
+    if (cp >= 0x00C0 && cp <= 0x017F) return 1;
+    if (cp >= 0x0370 && cp <= 0x03FF) return 1;
+    if (cp >= 0x0400 && cp <= 0x04FF) return 1;
+    if (cp >= 0x0600 && cp <= 0x06FF) return 1;
+    if (cp >= 0x05D0 && cp <= 0x05EA) return 1;
+    if (cp >= 0x0900 && cp <= 0x097F) return 1;
+    if (cp >= 0x4E00 && cp <= 0x9FFF) return 1;
+    if ((cp >= 0x3040 && cp <= 0x309F) ||
+        (cp >= 0x30A0 && cp <= 0x30FF)) return 1;
+    if (cp >= 0xAC00 && cp <= 0xD7A3) return 1;
+    if ((cp >= 0x0660 && cp <= 0x0669) ||
+        (cp >= 0x06F0 && cp <= 0x06F9)) return 1;
+
+    return 0;
+}
+
+// Check if string is a keyword
+int is_keyword(const char *word) {
+  for (int i = 0; c_keywords[i] != NULL; i++) {
+    if (strcmp(word, c_keywords[i]) == 0)
+      return 1;
+  }
+  return 0;
+}
+
+// Check if string is a type
+int is_type(const char *word) {
+  for (int i = 0; c_types[i] != NULL; i++) {
+    if (strcmp(word, c_types[i]) == 0)
+      return 1;
+  }
+  return 0;
+}
+
+// Get color code for token type
+const char *get_color(TokenType type) {
+  switch (type) {
+  case TOKEN_KEYWORD:
+    return E.theme.COLOR_KEYWORD;
+  case TOKEN_TYPE:
+    return E.theme.COLOR_TYPE;
+  case TOKEN_STRING:
+    return E.theme.COLOR_STRING;
+  case TOKEN_COMMENT:
+    return E.theme.COLOR_COMMENT;
+  case TOKEN_NUMBER:
+    return E.theme.COLOR_NUMBER;
+  default:
+    return E.theme.COLOR_DEFAULT;
+  }
+}
+
+int comment_section = 0;
+
+// Highlight a line of C code and return the highlighted string
+// Returns a newly allocated string that must be freed by the caller
+char *highlight_line(const char *line, int *length) {
+  // Each byte can expand to at most (color_prefix + 4 bytes + color_reset).
+  // Allocate generously based on line length to avoid overflow.
+  int line_len = strlen(line);
+  int buf_size = line_len * 32 + 256;
+  char *result = malloc(buf_size);
+  int result_pos = 0;
+  int i = 0;
+
+  while (line[i] != '\0' && line[i] != '\n') {
+    // Skip whitespace — copy full UTF-8 char (whitespace is always ASCII,
+    // but using copy_utf8_char keeps the pattern consistent)
+    if (line[i] == ' ' || line[i] == '\t') {
+      copy_utf8_char(result, &result_pos, line, &i);
+      continue;
+    }
+
+    if (comment_section) {
+      result_pos += sprintf(&result[result_pos], "%s", E.theme.COLOR_COMMENT);
+      while (line[i] != '\0' && line[i] != '\n') {
+        if (line[i] == '*' && line[i + 1] == '/') {
+          comment_section = 0;
+        }
+        copy_utf8_char(result, &result_pos, line, &i);
+      }
+      result_pos += sprintf(&result[result_pos], "%s", COLOR_RESET);
+      continue;
+    }
+
+    // Handle line comments
+    if (line[i] == '/' && line[i + 1] == '/') {
+      result_pos += sprintf(&result[result_pos], "%s", E.theme.COLOR_COMMENT);
+      while (line[i] != '\0' && line[i] != '\n') {
+        copy_utf8_char(result, &result_pos, line, &i);
+      }
+      result_pos += sprintf(&result[result_pos], "%s", COLOR_RESET);
+      continue;
+    }
+
+    // Handle block comments
+    if (line[i] == '/' && line[i + 1] == '*') {
+      comment_section = 1;
+      result_pos += sprintf(&result[result_pos], "%s", E.theme.COLOR_COMMENT);
+      result[result_pos++] = line[i++];
+      result[result_pos++] = line[i++];
+      while (line[i] != '\0') {
+        if (line[i] == '*' && line[i + 1] == '/') {
+          result[result_pos++] = line[i++];
+          result[result_pos++] = line[i++];
+          comment_section = 0;
+          break;
+        }
+        copy_utf8_char(result, &result_pos, line, &i);
+      }
+      result_pos += sprintf(&result[result_pos], "%s", COLOR_RESET);
+      continue;
+    }
+
+    // Handle strings
+    if (line[i] == '"') {
+      result_pos += sprintf(&result[result_pos], "%s\"", E.theme.COLOR_STRING);
+      i++;
+      while (line[i] != '\0' && line[i] != '"') {
+        if (line[i] == '\\') {
+          result[result_pos++] = line[i++];
+          copy_utf8_char(result, &result_pos, line, &i);
+        } else {
+          copy_utf8_char(result, &result_pos, line, &i);
+        }
+      }
+      if (line[i] == '"')
+        result[result_pos++] = line[i++];
+      result_pos += sprintf(&result[result_pos], "%s", COLOR_RESET);
+      continue;
+    }
+
+    // Handle character literals
+    if (line[i] == '\'') {
+      result_pos += sprintf(&result[result_pos], "%s'", E.theme.COLOR_STRING);
+      i++;
+      while (line[i] != '\0' && line[i] != '\'') {
+        if (line[i] == '\\') {
+          result[result_pos++] = line[i++];
+          copy_utf8_char(result, &result_pos, line, &i);
+        } else {
+          copy_utf8_char(result, &result_pos, line, &i);
+        }
+      }
+      if (line[i] == '\'')
+        result[result_pos++] = line[i++];
+      result_pos += sprintf(&result[result_pos], "%s", COLOR_RESET);
+      continue;
+    }
+
+    // Handle numbers
+    if (line[i] >= '0' && line[i] <= '9') {
+      result_pos += sprintf(&result[result_pos], "%s", E.theme.COLOR_NUMBER);
+      while (is_word_char(&line[i]) || line[i] == '.') {
+        copy_utf8_char(result, &result_pos, line, &i);
+      }
+      result_pos += sprintf(&result[result_pos], "%s", COLOR_RESET);
+      continue;
+    }
+
+    // Handle identifiers and keywords
+    if (is_word_char(&line[i])) {
+      int start = i;
+      // Advance by full UTF-8 character widths, not single bytes
+      while (line[i] != '\0' && is_word_char(&line[i]))
+        i += utf8_char_len(&line[i]);
+
+      char word[256];
+      int word_len = i - start;
+      if (word_len >= (int)sizeof(word))
+        word_len = (int)sizeof(word) - 1;
+      strncpy(word, &line[start], word_len);
+      word[word_len] = '\0';
+
+      TokenType type = TOKEN_DEFAULT;
+      if (is_keyword(word))
+        type = TOKEN_KEYWORD;
+      else if (is_type(word))
+        type = TOKEN_TYPE;
+
+      result_pos += sprintf(&result[result_pos], "%s%s%s", get_color(type),
+                            word, COLOR_RESET);
+      continue;
+    }
+
+    // Handle operators and other characters (including non-ASCII multi-byte)
+    result_pos += sprintf(&result[result_pos], "%s", E.theme.COLOR_DEFAULT);
+    copy_utf8_char(result, &result_pos, line, &i);
+    result_pos += sprintf(&result[result_pos], "%s", COLOR_RESET);
+  }
+
+  result[result_pos] = '\0';
+  *length = result_pos + 1;
+  return result;
+}

src/terminal.c

@@ -1,7 +1,16 @@
 #include "../include/terminal.h"
-#include "../include/data.h"
 
+#include <ctype.h>
+
+#include "../include/data.h"
+#include "../include/define.h"
+
+#include <stdarg.h>
 #include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "include/utf8.h"
 
 void die(const char *s) {
   write(STDOUT_FILENO, "\x1b[2J", 4);
@@ -35,26 +44,88 @@ void enableRawMode() {
   }
 }
 
-int editorReadKey() {
-  int nread;
-  char c;
-  char seq[3];
-  while ((nread = read(STDIN_FILENO, &c, 1)) != 1) {
-    if (nread == -1 && errno != EAGAIN) {
-      die("read");
+#include <ctype.h> /* isprint */
+
+char *keyToString(int key) {
+  static char key_str[32];
+
+  if (key == '\r') {
+    strcpy(key_str, "ENTER");
+  } else if (key == 0x09) {
+    strcpy(key_str, "TAB");
+  } else if (key >= 1 && key <= 26) {
+    snprintf(key_str, sizeof(key_str), "CTRL-%c", 'a' + key - 1);
+  } else {
+    switch (key) {
+    case ARROW_UP:
+      strcpy(key_str, "ARROW-UP");
+      break;
+    case ARROW_DOWN:
+      strcpy(key_str, "ARROW-DOWN");
+      break;
+    case ARROW_LEFT:
+      strcpy(key_str, "ARROW-LEFT");
+      break;
+    case ARROW_RIGHT:
+      strcpy(key_str, "ARROW-RIGHT");
+      break;
+    case PAGE_UP:
+      strcpy(key_str, "PAGE-UP");
+      break;
+    case PAGE_DOWN:
+      strcpy(key_str, "PAGE-DOWN");
+      break;
+    case DEL_KEY:
+      strcpy(key_str, "DEL");
+      break;
+    case BACKSPACE:
+      strcpy(key_str, "BACKSPACE");
+      break;
+    case BEG_LINE:
+      strcpy(key_str, "HOME");
+      break;
+    case END_LINE:
+      strcpy(key_str, "END");
+      break;
+    case '\x1b':
+      strcpy(key_str, "ESCAPE");
+      break;
+    default:
+      if (key > 127) {
+        /* UTF-8 code point — re-encode into the buffer */
+        char buf[5] = {0};
+        int n = utf8Encode((uint32_t)key, buf);
+        snprintf(key_str, sizeof(key_str), "%.*s", n, buf);
+      } else if (isprint(key)) {
+        snprintf(key_str, sizeof(key_str), "%c", key);
+      } else {
+        snprintf(key_str, sizeof(key_str), "KEY-%d", key);
+      }
     }
   }
+  return key_str;
+}
+
+int editorReadKey() {
+  char c;
+  /* read first byte — may be start of UTF-8 or escape */
+  while (read(STDIN_FILENO, &c, 1) != 1)
+    ;
+  appDebug("f : %hhu %ld\r\n", c, 0x200);
 
   if (c == '\x1b') {
-    if (read(STDIN_FILENO, &seq[0], 1) != 1 ||
-        read(STDIN_FILENO, &seq[1], 1) != 1) {
+    char seq[6];
+    /* try to read escape sequence */
+    if (read(STDIN_FILENO, &seq[0], 1) != 1)
       return '\x1b';
-    }
+    if (read(STDIN_FILENO, &seq[1], 1) != 1)
+      return '\x1b';
+    appDebug("f2 : %s\r\n", seq);
+
     if (seq[0] == '[') {
       if (seq[1] >= '0' && seq[1] <= '9') {
-        if (read(STDIN_FILENO, &seq[2], 1) != 1) {
+        if (read(STDIN_FILENO, &seq[2], 1) != 1)
           return '\x1b';
-        }
         if (seq[2] == '~') {
           switch (seq[1]) {
           case '1':
@@ -74,7 +145,6 @@ int editorReadKey() {
           }
         }
       } else {
-
         switch (seq[1]) {
         case 'A':
           return ARROW_UP;
@@ -90,18 +160,26 @@ int editorReadKey() {
           return END_LINE;
         }
       }
-    } else if (seq[0] == 'O') {
-      switch (seq[1]) {
-      case 'H':
-        return BEG_LINE;
-      case 'F':
-        return END_LINE;
-      }
     }
     return '\x1b';
-  } else {
-    return c;
   }
+
+  /* multi-byte UTF-8: read remaining bytes */
+  int seqlen = utf8Seqlen((unsigned char)c);
+  if (seqlen > 1) {
+    /* pack into a pseudo-codepoint just to pass bytes through;
+       we handle encoding/decoding at the row level */
+    char buf[4] = {c, 0, 0, 0};
+    for (int i = 1; i < seqlen; i++)
+      if (read(STDIN_FILENO, &buf[i], 1) != 1)
+        break;
+    /* decode and return as uint32, but we need int — use high range */
+    const char *p = buf;
+    uint32_t cp = utf8Decode(&p);
+    return (int)cp; /* caller re-encodes when inserting */
+  }
+
+  return (unsigned char)c;
 }
 
 int getCursorPosition(int *rows, int *cols) {
@@ -147,3 +225,14 @@ int getWindowSize(int *rows, int *cols) {
     return 0;
   }
 }
+
+void appDebug(const char *fmt, ...) {
+#ifdef APP_DEBUG
+  va_list ap;
+  char message[256];
+  va_start(ap, fmt);
+  vsnprintf(message, 256, fmt, ap);
+  va_end(ap);
+  fprintf(stderr, "%s\n", message);
+#endif
+}

src/utf8.c

@@ -0,0 +1,147 @@
+/**
+ * @file utf8.c
+ */
+
+#include "../include/utf8.h"
+
+#include <stdint.h>
+#include <unistd.h>
+
+
+uint32_t readUtf8Char(void)
+{
+    unsigned char buf[4];
+
+    read(STDIN_FILENO, &buf[0], 1);
+
+    int extra;
+    uint32_t cp;
+
+    if (buf[0] < 0x80)
+    {
+        cp = buf[0];
+        extra = 0;
+    }
+    else if (buf[0] < 0xC0) { return 0xFFFD; } // stray continuation
+    else if (buf[0] < 0xE0)
+    {
+        cp = buf[0] & 0x1F;
+        extra = 1;
+    }
+    else if (buf[0] < 0xF0)
+    {
+        cp = buf[0] & 0x0F;
+        extra = 2;
+    }
+    else
+    {
+        cp = buf[0] & 0x07;
+        extra = 3;
+    }
+
+    if (extra > 0)
+    {
+        read(STDIN_FILENO, &buf[1], extra); // read remaining bytes at once
+        for (int i = 0; i < extra; i++)
+            cp = (cp << 6) | (buf[1 + i] & 0x3F);
+    }
+
+    return cp;
+}
+
+uint32_t utf8Decode(const char** s)
+{
+    unsigned char c = (unsigned char)**s;
+    uint32_t cp;
+    int extra;
+    if (c < 0x80)
+    {
+        cp = c;
+        extra = 0;
+    }
+    else if (c < 0xC0)
+    {
+        (*s)++;
+        return 0xFFFD;
+    }
+    else if (c < 0xE0)
+    {
+        cp = c & 0x1F;
+        extra = 1;
+    }
+    else if (c < 0xF0)
+    {
+        cp = c & 0x0F;
+        extra = 2;
+    }
+    else
+    {
+        cp = c & 0x07;
+        extra = 3;
+    }
+    (*s)++;
+    while (extra--)
+    {
+        c = (unsigned char)**s;
+        if ((c & 0xC0) != 0x80) return 0xFFFD;
+        cp = (cp << 6) | (c & 0x3F);
+        (*s)++;
+    }
+    return cp;
+}
+
+// buf must have at least 4 bytes; returns bytes written
+int utf8Encode(uint32_t cp, char* buf)
+{
+    if (cp < 0x80)
+    {
+        buf[0] = cp;
+        return 1;
+    }
+    if (cp < 0x800)
+    {
+        buf[0] = 0xC0 | (cp >> 6);
+        buf[1] = 0x80 | (cp & 0x3F);
+        return 2;
+    }
+    if (cp < 0x10000)
+    {
+        buf[0] = 0xE0 | (cp >> 12);
+        buf[1] = 0x80 | ((cp >> 6) & 0x3F);
+        buf[2] = 0x80 | (cp & 0x3F);
+        return 3;
+    }
+    buf[0] = 0xF0 | (cp >> 18);
+    buf[1] = 0x80 | ((cp >> 12) & 0x3F);
+    buf[2] = 0x80 | ((cp >> 6) & 0x3F);
+    buf[3] = 0x80 | (cp & 0x3F);
+    return 4;
+}
+
+int utf8Seqlen(unsigned char c)
+{
+    if (c < 0x80) return 1;
+    if (c < 0xC0) return 0; /* continuation — shouldn't be leading */
+    if (c < 0xE0) return 2;
+    if (c < 0xF0) return 3;
+    return 4;
+}
+
+/**
+ * @param codepoint utf8 codepoint of a char
+ * @return length of the codepoint
+ */
+int codepointWidth(uint32_t codepoint)
+{
+    if (codepoint < 0x20 || codepoint == 0x7F) return 0;
+    /* rough double-width ranges */
+    if ((codepoint >= 0x1100 && codepoint <= 0x115F) ||
+        (codepoint >= 0x2E80 && codepoint <= 0x303E) ||
+        (codepoint >= 0x3041 && codepoint <= 0x33BF) ||
+        (codepoint >= 0xAC00 && codepoint <= 0xD7AF) ||
+        (codepoint >= 0xF900 && codepoint <= 0xFAFF) ||
+        (codepoint >= 0xFF01 && codepoint <= 0xFF60) ||
+        (codepoint >= 0x1F300 && codepoint <= 0x1FAFF))
+        return 2;
+    return 1;
+}