CE Implement line editing

ce/ce.c

@@ -1,29 +1,29 @@
 #include "arena_alloc.h"
 #include "context.h"
+#include "gapbuffer.h"
 #include "interp.h"
 #include "mprintf.h"
 #include "self.h"
 #include "strbuf.h"
 #include <arena.h>
-#include <desc.h>
-#include <filereader.h>
-#include <filewriter.h>
-#include <liballoc.h>
+#include <kb.h>
 #include <list.h>
-#include <minmax.h>
-#include <path.h>
 #include <printf.h>
-#include <process.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
-#include <str_status.h>
 #include <string.h>
 #include <system.h>
-#include <terminal_cursor.h>
+#include <tcursor.h>
+#include <tscreen.h>
 
-#define LINE_BUFFER_MAX 1024
-#define PROMPT          "$ "
+#define LINE_INIT_MAX 2
+#define PROMPT        "$ "
+
+struct edit_line {
+  struct gapbuffer gb;
+  size_t cursor;
+};
 
 static void exec_line (const char* line) {
   struct list_node_link* tokens = NULL;
@@ -32,39 +32,84 @@ static void exec_line (const char* line) {
 
   if (tokens != NULL)
     parse_and_execute (tokens);
-
-  arena_reset (&arena);
 }
 
 void app_main (void) {
   e_pid = get_exec_pid ();
   e_pgid = get_procgroup (e_pid);
 
-  size_t line_cursor = 0;
-  char line_buffer[LINE_BUFFER_MAX + 1];
-  memset (line_buffer, 0, sizeof (line_buffer));
+  struct edit_line edit_line;
+
+  const char* render = NULL;
 
   while (interp_is_running ()) {
+    gapbuffer_init (&edit_line.gb, LINE_INIT_MAX);
+    edit_line.cursor = 0;
+
     mprintf (PROMPT);
 
-    char ch = 0;
+    uint8_t ch = 0;
     for (;;) {
       mail_receive (&ch, 1);
 
       if (ch == '\n')
         break;
 
-      if (line_cursor < LINE_BUFFER_MAX) {
-        line_buffer[line_cursor++] = ch;
-        mprintf ("%c", ch);
+      switch (ch) {
+      case '\b':
+        if (edit_line.cursor > 0) {
+          gapbuffer_backspace (&edit_line.gb);
+          edit_line.cursor--;
+
+          mprintf ("\b");
+
+          char* tail = gapbuffer_string_at (&edit_line.gb, edit_line.cursor);
+          mprintf ("%s" ANSIQ_SCR_CLR2END, tail);
+
+          int move_back = (int)strlen (tail);
+          if (move_back > 0)
+            mprintf (ANSIQ_DYN_CUR_LEFT, move_back);
+        }
+        break;
+      case KB_LEFT:
+        if (edit_line.cursor > 0) {
+          edit_line.cursor--;
+          mprintf (ANSIQ_CUR_LEFT (1));
+        }
+        break;
+      case KB_RIGHT:
+        if (edit_line.cursor < gapbuffer_length (&edit_line.gb)) {
+          edit_line.cursor++;
+          mprintf (ANSIQ_CUR_RIGHT (1));
+        }
+        break;
+      default:
+        if (isascii (ch)) {
+          gapbuffer_insert (&edit_line.gb, ch);
+          edit_line.cursor++;
+
+          char* tail = gapbuffer_string_at (&edit_line.gb, edit_line.cursor - 1);
+          mprintf ("%s" ANSIQ_SCR_CLR2LEND, tail);
+
+          int move_back = (int)strlen (tail) - 1;
+          if (move_back > 0)
+            mprintf (ANSIQ_DYN_CUR_LEFT, move_back);
+        }
+        break;
       }
+
+      gapbuffer_move (&edit_line.gb, edit_line.cursor);
     }
 
     mprintf ("\n");
-    exec_line (line_buffer);
 
-    line_cursor = 0;
-    memset (line_buffer, 0, sizeof (line_buffer));
+    render = gapbuffer_get_string (&edit_line.gb);
+
+    if (render != NULL)
+      exec_line (render);
+
+    gapbuffer_fini (&edit_line.gb);
+    arena_reset (&arena);
   }
 
   arena_destroy (&arena);