Rearrange code and cleanup

src/editor/indents.cc

@@ -0,0 +1,87 @@
+#include "editor/editor.h"
+
+uint32_t leading_indent(const char *line, uint32_t len) {
+  uint32_t indent = 0;
+  for (uint32_t i = 0; i < len; i++) {
+    if (line[i] == ' ')
+      indent++;
+    else if (line[i] == '\t')
+      indent += INDENT_WIDTH;
+    else
+      break;
+  }
+  return indent;
+}
+
+uint32_t get_indent(Editor *editor, Coord cursor) {
+  if (!editor)
+    return 0;
+  LineIterator *it = begin_l_iter(editor->root, cursor.row);
+  next_line(it, nullptr);
+  uint32_t line_len;
+  char *line;
+  while ((line = prev_line(it, &line_len)) != nullptr) {
+    if (line_len == 0)
+      continue;
+    uint32_t indent = leading_indent(line, line_len);
+    free(it->buffer);
+    free(it);
+    return indent;
+  }
+  free(it->buffer);
+  free(it);
+  return 0;
+}
+
+bool closing_after_cursor(const char *line, uint32_t len, uint32_t col) {
+  uint32_t i = col;
+  while (i < len && (line[i] == ' ' || line[i] == '\t'))
+    i++;
+  if (i >= len)
+    return false;
+  return line[i] == '}' || line[i] == ']' || line[i] == ')';
+}
+
+void indent_line(Editor *editor, uint32_t row) {
+  if (!editor)
+    return;
+  LineIterator *it = begin_l_iter(editor->root, row);
+  uint32_t line_len;
+  char *line = next_line(it, &line_len);
+  if (!line) {
+    free(it->buffer);
+    free(it);
+    return;
+  }
+  char *spaces = (char *)malloc(INDENT_WIDTH);
+  memset(spaces, ' ', INDENT_WIDTH);
+  Coord cursor = editor->cursor;
+  edit_insert(editor, {row, 0}, spaces, INDENT_WIDTH);
+  editor->cursor = cursor;
+  free(spaces);
+  free(it->buffer);
+  free(it);
+}
+
+void dedent_line(Editor *editor, uint32_t row) {
+  if (!editor)
+    return;
+  LineIterator *it = begin_l_iter(editor->root, row);
+  uint32_t line_len;
+  char *line = next_line(it, &line_len);
+  if (!line) {
+    free(it->buffer);
+    free(it);
+    return;
+  }
+  uint32_t indent = leading_indent(line, line_len);
+  if (indent == 0) {
+    free(it->buffer);
+    free(it);
+    return;
+  }
+  uint32_t remove = indent >= INDENT_WIDTH ? INDENT_WIDTH : indent;
+  edit_erase(editor, {row, 0}, remove);
+  free(it->buffer);
+  free(it);
+}