Finish refactoring

README.md

@@ -20,7 +20,7 @@ gcc -I include src/*.c -o kilo
 
 ## My additions
 - Split it up into multiple files and tried to follow good design and
-organization practices (WIP).
+organization practices.
 
 ## References
 - [antirez/kilo][1]

include/buffer.h

@@ -4,8 +4,10 @@
 #include <stdbool.h>
 #include <stddef.h>
 
-#include "utils.h"
 #include "erow.h"
+#include "utils.h"
+
+struct erow;
 
 struct buffer {
     char *filename;
@@ -25,6 +27,7 @@ ERRCODE buffer_write_file(struct buffer *buffer, size_t *bytes_written);
 void buffer_insert_row(struct buffer *buffer, struct erow *erow, int at);
 void buffer_delete_row(struct buffer *buffer, int at);
 struct erow *buffer_get_crow(struct buffer *buffer);
+size_t buffer_get_crow_len(struct buffer *buffer);
 void buffer_free(struct buffer *buffer);
 
 

include/cursor.h

@@ -0,0 +1,10 @@
+#ifndef CURSOR_H
+#define CURSOR_H
+
+#include "buffer.h"
+
+struct buffer;
+
+void cursor_move(struct buffer *buffer, int dx, int dy);
+
+#endif // CURSOR_H

include/erow.h

@@ -3,6 +3,8 @@
 
 #include <stdlib.h>
 
+struct buffer;
+
 struct erow {
     char *chars;
     size_t n_chars;
@@ -15,7 +17,7 @@ struct erow {
 
 struct erow *erow_create(const char* chars, size_t n_chars, struct buffer *buffer);
 void erow_insert_chars(struct erow *erow, const char *chars, size_t n_chars, int at);
-void erow_delete_char(struct erow *erow, int at);
+void erow_delete_chars(struct erow *erow, size_t n_chars, int at);
 int erow_cx_to_rx(struct erow *erow, int cx);
 int erow_rx_to_cx(struct erow *erow, int rx);
 void erow_free(struct erow *erow);

include/input.h

@@ -3,6 +3,8 @@
 
 #include <stdint.h>
 
+#define CTRL_KEY(key) ((key) & 0x1f)
+
 enum KEYS {
     TAB = 9,
     ENTER = 13,
@@ -21,6 +23,6 @@ enum KEYS {
 };
 typedef uint16_t KEY;
 
-void input_process_key(void);
+void input_process_key(KEY c);
 
 #endif // INPUT_H

include/utils.h

@@ -1,10 +1,9 @@
 #ifndef UTIL_H
 #define UTIL_H
 
-#define CTRL_KEY(key) ((key) & 0x1f)
-
 #define MAX(a,b) (((a)>(b))?(a):(b))
 #define MIN(a,b) (((a)<(b))?(a):(b))
+#define CLAMP(value, min, max) MIN(MAX(value, min), max)
 
 #define _STRINGIZE(x) #x
 #define STRINGIZE(x) _STRINGIZE(x)

progress_log.md

@@ -1,4 +1,5 @@
 # Progress log
+
 - (4/9/2023) Finished 5 chapters out of 7, basic text editing is fully
 possible. It has fun been working on this, but semester is starting now and I
 might not get to work on this a lot anymore. It might have lots of bugs, and
@@ -6,3 +7,11 @@ there's lots of things I don't like, there are TODOs everywhere. So many leaky
 abstractions, near the end I started blindly following the tutorial and didn't
 stop to think how it fits with the abstractions I have defined, but I might fix
 it all one of these days...
+
+- (9/9/2023) Didn't implement any new features, but refactored heavily. All the
+previous features should be working unless I introduced a bug. But I like the
+abstractions better now, and I cleaned up most of TODOs. This was painful to
+get right and I contemplated quitting, but proud of myself. I find it very
+interesting that the total of amount of code barely changed, it actually
+decreased as measured by tokei. It increased slightly in the header files and
+decreased in the source files, yet it was a lot of work.

src/buffer.c

@@ -1,4 +1,6 @@
+#include <stdbool.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include "buffer.h"
@@ -36,7 +38,6 @@ ERRCODE buffer_read_file(struct buffer *buffer, const char *filename) {
         buffer_free_rows(buffer);
 
     size_t buf_cap = 64;
-    size_t buf_size = 0;
     char *buf = malloc(buf_cap);
 
     FILE *file = fopen(filename, "r");
@@ -45,6 +46,7 @@ ERRCODE buffer_read_file(struct buffer *buffer, const char *filename) {
 
     while (true) {
         char c;
+        size_t buf_size = 0;
 
         while ((c = getc(file)) != '\n' && c != EOF) {
             if (buf_size >= buf_cap)
@@ -139,7 +141,6 @@ void buffer_insert_row(struct buffer *buffer, struct erow *erow, int at) {
     memmove(buffer->rows + at + 1, buffer->rows + at, sizeof(struct erow *) * (buffer->n_rows - at));
 
     buffer->rows[at] = erow;
-
     buffer->n_rows++;
 }
 
@@ -164,6 +165,12 @@ void buffer_free(struct buffer *buffer) {
     buffer_free_rows(buffer);
 }
 
+size_t buffer_get_crow_len(struct buffer *buffer) {
+    struct erow *crow = buffer_get_crow(buffer);
+
+    return crow ? crow->n_chars : 0;
+}
+
 static void buffer_free_rows(struct buffer *buffer) {
     for (int i = 0; i < buffer->n_rows; i++)
         erow_free(buffer->rows[i]);

src/commands.c

@@ -1,19 +1,16 @@
 #include <errno.h>
-#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "buffer.h"
 #include "commands.h"
+#include "cursor.h"
+#include "erow.h"
 #include "input.h"
 #include "kilo.h"
 #include "terminal.h"
 #include "utils.h"
 
-static void cursor_adjust_viewport(void);
-static void cursor_check_file_bounds(bool horizontal);
-static void cursor_update_rx(bool horizontal);
-
 void command_quit(void) {
     if (E.current_buf->modified && E.quit_times) {
         editor_set_message("Unsaved changed! Press quit %d more time(s)", E.quit_times);
@@ -25,110 +22,87 @@ void command_quit(void) {
 }
 
 void command_move_cursor(KEY key) {
-    struct erow *rows = E.current_buf->rows;
-    int n_rows = E.current_buf->n_rows;
-
-    struct erow *erow = (rows && E.cy < n_rows ? rows + E.cy : NULL);
-    int max_x = (erow ? erow->n_chars : 0);
-
     switch (key) {
         case ARROW_LEFT:
-            E.cx--;
+            cursor_move(E.current_buf, -1, 0);
             break;
         case ARROW_DOWN:
-            E.cy++;
+            cursor_move(E.current_buf, 0, 1);
             break;
         case ARROW_UP:
-            E.cy--;
+            cursor_move(E.current_buf, 0, -1);
             break;
         case ARROW_RIGHT:
-            E.cx++;
+            cursor_move(E.current_buf, 1, 0);
             break;
 
         case HOME:
-            E.cx = 0;
+            cursor_move(E.current_buf, -E.current_buf->cx, 0);
             break;
         case END:
-            E.cx = max_x;
+            cursor_move(E.current_buf, buffer_get_crow_len(E.current_buf) - E.current_buf->cx, 0);
             break;
 
         case PG_UP:
-            E.cy -= E.screenrows;
+            cursor_move(E.current_buf, 0, -E.screenrows);
             break;
         case PG_DOWN:
-            E.cy += E.screenrows;
+            cursor_move(E.current_buf, 0, E.screenrows);
             break;
     }
-
-    bool horizontal = (key == ARROW_LEFT  || 
-        key == ARROW_RIGHT ||
-        key == HOME        ||
-        key == END);
-
-    cursor_check_file_bounds(horizontal);
-    cursor_update_rx(horizontal);
-    cursor_adjust_viewport();
 }
 
-// TODO: Improve this
 void command_insert_line(void) {
-    if (E.cy == E.current_buf->n_rows) {
-        buffer_insert_row(E.current_buf, NULL, 0, E.cy);
+    struct erow *erow = erow_create(NULL, 0, E.current_buf);
+
+    if (E.current_buf->cy == E.current_buf->n_rows) {
+        buffer_insert_row(E.current_buf, erow, E.current_buf->cy);
     } else {
-        buffer_insert_row(E.current_buf, NULL, 0, E.cy + 1);
+        buffer_insert_row(E.current_buf, erow, E.current_buf->cy + 1);
 
-        struct erow *c_row = E.current_buf->rows + E.cy;
-        struct erow *n_row = E.current_buf->rows + E.cy + 1;
+        struct erow *crow = buffer_get_crow(E.current_buf);
 
-        erow_append_string(n_row, c_row->chars + E.cx, c_row->n_chars - E.cx);
-
-        c_row->chars = realloc(c_row->chars, E.cx);
-        c_row->n_chars = E.cx;
-        erow_update_rendering(c_row);
+        erow_insert_chars(erow, crow->chars + E.current_buf->cx, crow->n_chars - E.current_buf->cx, 0);
+        erow_delete_chars(crow, crow->n_chars - E.current_buf->cx, E.current_buf->cx);
     }
 
-    E.cx = E.rx = 0;
-    E.cy++;
-
-    cursor_adjust_viewport();
+    input_process_key(ARROW_DOWN);
+    input_process_key(HOME);
 }
 
 void command_insert_char(char c) {
-    if (E.cy == E.current_buf->n_rows)
-        buffer_insert_row(E.current_buf, NULL, 0, E.current_buf->n_rows);
+    struct erow *erow;
 
-    erow_insert_char(E.current_buf->rows+E.cy, E.cx++, c);
-    E.rx = erow_cx_to_rx(E.current_buf->rows+E.cy, E.cx);
+    if (E.current_buf->cy == E.current_buf->n_rows) {
+        erow = erow_create(NULL, 0, E.current_buf);
+        buffer_insert_row(E.current_buf, erow, E.current_buf->n_rows);
+    } else erow = buffer_get_crow(E.current_buf);
 
-    cursor_adjust_viewport();
+    erow_insert_chars(erow, &c, 1, E.current_buf->cx);
+    input_process_key(ARROW_RIGHT);
 }
 
-void command_delete_char(void) { // TODO
-    if (E.cx == 0 && E.cy == 0) return;
-    if (E.cy == E.current_buf->n_rows) {
-        E.cx = E.current_buf->rows[--E.cy].n_chars;
-        E.rx = erow_cx_to_rx(E.current_buf->rows+E.cy, E.cx);
-        return;
+void command_delete_char(void) {
+    if (E.current_buf->cy == E.current_buf->n_rows)
+        input_process_key(ARROW_LEFT);
+
+    struct erow *crow = buffer_get_crow(E.current_buf);
+
+    if (E.current_buf->cx == 0) {
+        if (E.current_buf->cy == 0)
+            return;
+
+        struct erow *prow = E.current_buf->rows[E.current_buf->cy - 1];
+
+        input_process_key(ARROW_UP);
+        cursor_move(E.current_buf, prow->n_chars, 0);
+
+        erow_insert_chars(prow, crow->chars, crow->n_chars, prow->n_chars);
+        buffer_delete_row(E.current_buf, E.current_buf->cy + 1);
+    } else {
+        erow_delete_chars(crow, 1, E.current_buf->cx - 1);
+        input_process_key(ARROW_LEFT);
     }
-
-    if (E.cx > 0) {
-        erow_delete_char(E.current_buf->rows+E.cy, E.cx - 1);
-    }
-    else {
-        struct erow *c_row = E.current_buf->rows + E.cy;
-        struct erow *p_row = E.current_buf->rows + E.cy - 1;
-
-        E.cx = p_row->n_chars;
-
-        erow_append_string(p_row, c_row->chars, c_row->n_chars);
-        buffer_delete_row(E.current_buf, E.cy);
-
-        E.cy--;
-    }
-
-    E.rx = erow_cx_to_rx(E.current_buf->rows+E.cy, E.cx);
-
-    cursor_adjust_viewport();
 }
 
 void command_save_buffer(void) {
@@ -140,79 +114,11 @@ void command_save_buffer(void) {
         }
     }
 
-    int bytes_written;
+    size_t bytes_written;
     ERRCODE errcode = buffer_write_file(E.current_buf, &bytes_written);
 
     if (errcode == 0)
         editor_set_message("%d bytes written", bytes_written);
     else
-        editor_set_message("Save failed: ERRCODE %d: %s", errcode, strerror(errno));
-}
-
-static void cursor_check_file_bounds(bool horizontal) {
-    struct erow *rows = E.current_buf->rows;
-    int n_rows = E.current_buf->n_rows;
-
-    struct erow *erow = (rows && E.cy < n_rows ? rows + E.cy : NULL);
-    int max_x = (erow ? erow->n_chars : 0);
-
-    if (E.cy < 0)
-        E.cy = 0;
-
-    if (E.cy > n_rows)
-        E.cy = n_rows;
-
-    if (E.cx < 0) {
-        if (E.cy > 0 && horizontal)
-        {
-            erow = &rows[--E.cy];
-            max_x = erow->n_chars;
-
-            E.cx = max_x;
-        }
-        else E.cx = 0;
-    }
-
-    if (E.cx > max_x) {
-        if (E.cy < n_rows && horizontal) {
-            E.cx = 0;
-            E.cy++;
-        } else E.cx = max_x;
-    }
-}
-
-static void cursor_update_rx(bool horizontal) {
-    struct erow *rows = E.current_buf->rows;
-    int n_rows = E.current_buf->n_rows;
-
-    struct erow *erow = (rows && E.cy < n_rows ? rows + E.cy : NULL);
-    int max_x = (erow ? erow->n_chars : 0);
-
-    static int saved_rx = 0;
-    if (horizontal) saved_rx = erow_cx_to_rx(erow, E.cx);
-    else {
-        E.cx = erow_rx_to_cx(erow, saved_rx);
-        if (E.cx > max_x)
-            E.cx = max_x;
-    }
-
-    E.rx = erow_cx_to_rx(rows + E.cy, E.cx);
-}
-
-static void cursor_adjust_viewport(void) {
-    int max_row_off = E.cy;
-    if (E.row_off > max_row_off)
-        E.row_off = max_row_off;
-
-    int max_col_off = E.rx;
-    if (E.col_off > max_col_off)
-        E.col_off = max_col_off;
-
-    int min_row_off = E.cy - (E.screenrows - 1);
-    if (E.row_off < min_row_off)
-        E.row_off = min_row_off;
-
-    int min_col_off = E.rx - (E.screencols - 1);
-    if (E.col_off < min_col_off)
-        E.col_off = min_col_off;
+        editor_set_message("Write error %d: %s", errcode, strerror(errno));
 }

src/cursor.c

@@ -0,0 +1,45 @@
+#include "buffer.h"
+#include "cursor.h"
+#include "erow.h"
+#include "kilo.h"
+#include "utils.h"
+
+static void cursor_adjust_viewport(struct buffer *buffer);
+
+void cursor_move(struct buffer *buffer, int dx, int dy) {
+    static int saved_rx = 0;
+
+    buffer->cy = CLAMP(buffer->cy + dy, 0, buffer->n_rows);
+
+    if (dx == 0)
+        E.current_buf->cx = erow_rx_to_cx(buffer_get_crow(E.current_buf), saved_rx);
+
+    int new_x = buffer->cx + dx, max_x = buffer_get_crow_len(buffer);
+    if (new_x < 0) {
+        if (buffer->cy > 0) {
+            buffer->cy--;
+            buffer->cx = buffer_get_crow_len(buffer);
+        } else buffer->cx = 0;
+    } else if (new_x > max_x) {
+        if (buffer->cy < buffer->n_rows) {
+            buffer->cy++;
+            buffer->cx = 0;
+        } else buffer->cx = max_x;
+    } else buffer->cx = new_x;
+
+    cursor_adjust_viewport(buffer);
+    buffer->rx = erow_cx_to_rx(buffer_get_crow(buffer), buffer->cx);
+
+    if (dy == 0)
+        saved_rx = buffer->rx;
+}
+
+static void cursor_adjust_viewport(struct buffer *buffer) {
+    int min_row_off = buffer->cy - (E.screenrows - 1);
+    int max_row_off = buffer->cy;
+    buffer->row_off = CLAMP(buffer->row_off, min_row_off, max_row_off);
+
+    int min_col_off = buffer->rx - (E.screencols - 1);
+    int max_col_off = buffer->rx;
+    buffer->col_off = CLAMP(buffer->col_off, min_col_off, max_col_off);
+}

src/erow.c

@@ -1,9 +1,11 @@
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "buffer.h"
 #include "erow.h"
 #include "kilo.h"
+#include "utils.h"
 
 static void erow_update_rchars(struct erow *erow);
 
@@ -14,6 +16,8 @@ struct erow *erow_create(const char* chars, size_t n_chars, struct buffer *buffe
     erow->n_chars = n_chars;
 
     memcpy(erow->chars, chars, erow->n_chars);
+
+    erow->rchars = NULL;
     erow_update_rchars(erow);
 
     erow->buffer = buffer;
@@ -23,7 +27,7 @@ struct erow *erow_create(const char* chars, size_t n_chars, struct buffer *buffe
 
 void erow_insert_chars(struct erow *erow, const char *chars, size_t n_chars, int at) {
     erow->chars = realloc(erow->chars, erow->n_chars + n_chars);
-    memmove(erow->chars + at + n_chars, erow->chars + at, n_chars - at);
+    memmove(erow->chars + at + n_chars, erow->chars + at, erow->n_chars - at);
     memcpy(erow->chars + at, chars, n_chars);
 
     erow->n_chars += n_chars;
@@ -34,9 +38,9 @@ void erow_insert_chars(struct erow *erow, const char *chars, size_t n_chars, int
         erow->buffer->modified = true;
 }
 
-void erow_delete_char(struct erow *erow, int at) {
-    memmove(erow->chars + at, erow->chars + at + 1, erow->n_chars - at);
-    erow->chars = realloc(erow->chars, --erow->n_chars);
+void erow_delete_chars(struct erow *erow, size_t n_chars, int at) {
+    memmove(erow->chars + at, erow->chars + at + n_chars, erow->n_chars - at - n_chars);
+    erow->chars = realloc(erow->chars, erow->n_chars -= n_chars);
 
     erow_update_rchars(erow);
 
@@ -45,6 +49,11 @@ void erow_delete_char(struct erow *erow, int at) {
 }
 
 int erow_cx_to_rx(struct erow *erow, int cx) {
+    if (erow == NULL)
+        return 0;
+
+    cx = CLAMP(cx, 0, (int) erow->n_chars);
+
     int rx = 0;
 
     for (char *c = erow->chars; c < erow->chars + cx; c++) {
@@ -58,17 +67,18 @@ int erow_cx_to_rx(struct erow *erow, int cx) {
 }
 
 int erow_rx_to_cx(struct erow *erow, int rx) {
-    if ((size_t) rx >= erow->n_rchars)
-        return erow->n_chars;
+    if (erow == NULL)
+        return 0;
 
-    int c_rx = 0;
-
-    for (int cx = 0; (size_t) cx < erow->n_chars; cx++) {
+    int cx = 0, c_rx = 0;
+    while ((size_t) cx < erow->n_chars) {
         if (erow->chars[cx] == '\t')
             c_rx += KILO_TAB_STOP - (c_rx % KILO_TAB_STOP);
         else
             c_rx++;
 
+        cx++;
+
         if (c_rx >= rx)
             return cx;
     }
@@ -86,7 +96,7 @@ static void erow_update_rchars(struct erow *erow) {
         free(erow->rchars);
 
     size_t n_rchars_max = 16;
-    erow->rchars = malloc(erow->n_rchars);
+    erow->rchars = malloc(n_rchars_max);
     erow->n_rchars = 0;
 
     for (char *c = erow->chars; c < erow->chars + erow->n_chars; c++) {

src/input.c

@@ -1,12 +1,8 @@
 #include "commands.h"
 #include "input.h"
 #include "kilo.h"
-#include "terminal.h"
-#include "utils.h"
-
-void input_process_key(void) {
-    KEY c = terminal_read_key();
 
+void input_process_key(KEY c) {
     switch (c) {
         case ARROW_LEFT:
         case ARROW_DOWN:
@@ -20,7 +16,7 @@ void input_process_key(void) {
             break;
 
         case CTRL_KEY('S'):
-            command_save_buffer();
+            // command_save_buffer();
             break;
 
         case ENTER:
@@ -28,7 +24,7 @@ void input_process_key(void) {
             break;
 
         case DEL:
-            command_move_cursor(ARROW_RIGHT);
+            input_process_key(ARROW_RIGHT);
         case BACKSPACE:
         case CTRL_KEY('H'):
             command_delete_char();

src/kilo.c

@@ -22,7 +22,7 @@ int main(int argc, char **argv) {
 
     while (true) {
         ui_draw_screen();
-        input_process_key();
+        input_process_key(terminal_read_key());
     }
 
     return 0;

src/ui.c

@@ -6,6 +6,7 @@
 #include <unistd.h>
 
 #include "buffer.h"
+#include "erow.h"
 #include "kilo.h"
 #include "terminal.h"
 #include "ui.h"
@@ -44,7 +45,7 @@ static void ui_draw_rows(struct append_buf *draw_buf) {
         bool no_file = (E.current_buf->filename == NULL && E.current_buf->n_rows == 0);
 
         if (in_file) {
-            struct erow *crow = buffer_get_crow(E.current_buf);
+            struct erow *crow = E.current_buf->rows[y + E.current_buf->row_off];
 
             size_t len = crow->n_rchars - E.current_buf->col_off;
             len = MIN(len, (size_t) E.screencols);