function findWord()

in lib/ace/keyboard/vim.js [4240:4298]
53 lines of code
23 McCabe index (conditional complexity)

    function findWord(cm, cur, forward, bigWord, emptyLineIsWord) {
      var lineNum = cur.line;
      var pos = cur.ch;
      var line = cm.getLine(lineNum);
      var dir = forward ? 1 : -1;
      var charTests = bigWord ? bigWordCharTest: wordCharTest;

      if (emptyLineIsWord && line == '') {
        lineNum += dir;
        line = cm.getLine(lineNum);
        if (!isLine(cm, lineNum)) {
          return null;
        }
        pos = (forward) ? 0 : line.length;
      }

      while (true) {
        if (emptyLineIsWord && line == '') {
          return { from: 0, to: 0, line: lineNum };
        }
        var stop = (dir > 0) ? line.length : -1;
        var wordStart = stop, wordEnd = stop;
        // Find bounds of next word.
        while (pos != stop) {
          var foundWord = false;
          for (var i = 0; i < charTests.length && !foundWord; ++i) {
            if (charTests[i](line.charAt(pos))) {
              wordStart = pos;
              // Advance to end of word.
              while (pos != stop && charTests[i](line.charAt(pos))) {
                pos += dir;
              }
              wordEnd = pos;
              foundWord = wordStart != wordEnd;
              if (wordStart == cur.ch && lineNum == cur.line &&
                  wordEnd == wordStart + dir) {
                // We started at the end of a word. Find the next one.
                continue;
              } else {
                return {
                  from: Math.min(wordStart, wordEnd + 1),
                  to: Math.max(wordStart, wordEnd),
                  line: lineNum };
              }
            }
          }
          if (!foundWord) {
            pos += dir;
          }
        }
        // Advance to next/prev line.
        lineNum += dir;
        if (!isLine(cm, lineNum)) {
          return null;
        }
        line = cm.getLine(lineNum);
        pos = (dir > 0) ? 0 : line.length;
      }
    }