Function translateRegex

lib/web/CodeMirror/keymap/vim.js:4161–4197

(str)

    // Translates a search string from ex (vim) syntax into javascript form.
    function translateRegex(str) {
      // When these match, add a '\' if unescaped or remove one if escaped.
      var specials = '|(){';
      // Remove, but never add, a '\' for these.
      var unescape = '}';
      var escapeNextChar = false;
      var out = [];
      for (var i = -1; i < str.length; i++) {
        var c = str.charAt(i) || '';
        var n = str.charAt(i+1) || '';
        var specialComesNext = (n && specials.indexOf(n) != -1);
        if (escapeNextChar) {
          if (c !== '\\' || !specialComesNext) {
            out.push(c);
          }
          escapeNextChar = false;
        } else {
          if (c === '\\') {
            escapeNextChar = true;
            // Treat the unescape list as special for removing, but not adding '\'.
            if (n && unescape.indexOf(n) != -1) {
              specialComesNext = true;
            }
            // Not passing this test means removing a '\'.
            if (!specialComesNext || n === '\\') {
              out.push(c);
            }
          } else {
            out.push(c);
            if (specialComesNext && n !== '\\') {
              out.push('\\');
            }
          }
        }
      }
      return out.join('');
    }

    // Translates the replace part of a search and replace from ex (vim) syntax into
    // javascript form.  Similar to translateRegex, but additionally fixes back references