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…ackspacing-at-the-start-of-a-line

kilo.c

@@ -258,6 +258,14 @@ void editorRowInsertChar(erow *row, int at, int c) {
   E.dirty++;
 }
 
+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++;
+}
+
 /*** editor operations ***/
 
 void editorInsertChar(int c) {
@@ -269,6 +277,16 @@ void editorInsertChar(int c) {
   E.cx++;
 }
 
+void editorDelChar() {
+  if (E.cy == E.numrows) return;
+
+  erow *row = &E.row[E.cy];
+  if (E.cx > 0) {
+    editorRowDelChar(row, E.cx - 1);
+    E.cx--;
+  }
+}
+
 /*** file i/o ***/
 
 char *editorRowsToString(int *buflen) {
@@ -438,7 +456,8 @@ void editorProcessKeyPress() {
     case BACKSPACE:
     case CTRL_KEY('h'):
     case DEL_KEY:
-      // TODO
+      if (c == DEL_KEY) editorMoveCursor(ARROW_RIGHT);
+      editorDelChar();
       break;
 
     case PAGE_UP: