Function clipToLine

src/codemirror.js:12350–12376

(cm, curStart, curEnd)

    // 'dw' should word, but not the newline, while 'w' should advance the
    // caret to the first character of the next line.
    function clipToLine(cm, curStart, curEnd) {
      var selection = cm.getRange(curStart, curEnd);
      // Only clip if the selection ends with trailing newline + whitespace
      if (/\n\s*$/.test(selection)) {
        var lines = selection.split('\n');
        // We know this is all whitespace.
        lines.pop();

        // Cases:
        // 1. Last word is an empty line - do not clip the trailing '\n'
        // 2. Last word is not an empty line - clip the trailing '\n'
        var line;
        // Find the line containing the last word, and clip all whitespace up
        // to it.
        for (var line = lines.pop(); lines.length > 0 && line && isWhiteSpaceString(line); line = lines.pop()) {
          curEnd.line--;
          curEnd.ch = 0;
        }
        // If the last word is not an empty line, clip an additional newline
        if (line) {
          curEnd.line--;
          curEnd.ch = lineLength(cm, curEnd.line);
        } else {
          curEnd.ch = 0;
        }
      }
    }

    // Expand the selection to line ends.
    function expandSelectionToLine(_cm, curStart, curEnd) {