Function findFatArrow

lib/web/CodeMirror/mode/javascript/javascript.js:184–217

(stream, state)

  // arrow, and not declare the arguments as locals for the arrow
  // body.
  function findFatArrow(stream, state) {
    if (state.fatArrowAt) state.fatArrowAt = null;
    var arrow = stream.string.indexOf("=>", stream.start);
    if (arrow < 0) return;

    if (isTS) { // Try to skip TypeScript return type declarations after the arguments
      var m = /:\s*(?:\w+(?:<[^>]*>|\[\])?|\{[^}]*\})\s*$/.exec(stream.string.slice(stream.start, arrow))
      if (m) arrow = m.index
    }

    var depth = 0, sawSomething = false;
    for (var pos = arrow - 1; pos >= 0; --pos) {
      var ch = stream.string.charAt(pos);
      var bracket = brackets.indexOf(ch);
      if (bracket >= 0 && bracket < 3) {
        if (!depth) { ++pos; break; }
        if (--depth == 0) { if (ch == "(") sawSomething = true; break; }
      } else if (bracket >= 3 && bracket < 6) {
        ++depth;
      } else if (wordRE.test(ch)) {
        sawSomething = true;
      } else if (/["'\/`]/.test(ch)) {
        for (;; --pos) {
          if (pos == 0) return
          var next = stream.string.charAt(pos - 1)
          if (next == ch && stream.string.charAt(pos - 2) != "\\") { pos--; break }
        }
      } else if (sawSomething && !depth) {
        ++pos;
        break;
      }
    }
    if (sawSomething && !depth) state.fatArrowAt = pos;
  }

  // Parser