代码增加行号

script

// Number the selected lines (or all lines) with colon and
   // two spaces after each line number.
   
   
   // Function for right-justifying text str in width n.
   function rjust(str, n) {
     var strLen = str.length;
     if (n > strLen) {
       var prefix = ' '.repeat(n - strLen)
      return prefix + str;
    } else {
      return str;
    }
  }
  
  // Get either the current selection or the entire draft.
  var sel = editor.getSelectedText();
  if (!sel || sel.length==0) {
    editor.setSelectedRange(0, editor.getText().length);
    sel = editor.getSelectedText();
    }
  
  // Break the text into lines and number them.
  // Right-justify the numbers and put a colon and
  // two spaces after the line number.
  var lines = sel.split('\n');
  var numLines = lines.length;
  var width = Math.floor(Math.log(numLines)*Math.LOG10E) + 1;
  var numbered = [];
  var lNum;
  for (var i=0; i<numLines; i++) {
    lNum = i + 1;
    numbered.push(rjust(lNum.toString(), width) + ':  ' + lines[i]);
  }
  
  // Replace the original text with the line-numbered text.
  editor.setSelectedText(numbered.join('\n'));