UltraEdit - align at pattern

// Align selected text lines at a given pattern or substring

var alignAt   = UltraEdit.getString("Align at pattern",1);
var alignAtPattern = new RegExp( alignAt );

// Cut selectedLines into clipboard
// include cutSelection.js

// First Pass: Compute match positions and their maximum

var pos = selectedLines.map( function(line) {
  return line.search( alignAtPattern );
  });
var maxPos = Math.max.apply(null,pos);

// Second pass: Perform the alignment
if (maxPos >= 0) {
  spaces = new Array(maxPos).join(' ');  // = ' ' x maxPos
  var result = selectedLines.map( function(line, i ) {
    if (pos[i]<0) {
// Pattern doesn't match? Leave line unchanged
      return line;
      }
    else {
// Pattern matches: Insert correct number of spaces
      return line.substring( 0, pos[i] ) +
             spaces.substring(0,maxPos-pos[i]) +
             line.substring(pos[i])
      }
    }).join(lineEnd);
  UltraEdit.activeDocument.write( result );
  }
else {
  UltraEdit.activeDocument.paste();
  }