Basic indentation support

src/editor_indents.cc

@@ -0,0 +1,40 @@
+#include "../include/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);
+  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(line);
+    free(it);
+    return indent;
+  }
+  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] == ')';
+}