Node.js definition aligner

gistfile1.js

#!/usr/bin/env node

process.stdin.resume();
process.stdin.setEncoding('utf8');

var isObjExp      = /^\s*[^:^\/]+\s*:\s*[^\/]/;
var objExp        = /^\s*([^:]+):\s*/;
var objSpaceExp   = /^\s*([^:]+\s*):/;
var varExp        = /^\s*([^=]+)\s*=[^=]/;
var varSpaceExp   = /^\s*([^=]+\s*)=[^=]/;
var wordExp, spaceExp, symbol, symbolExp, paddedSymbolExp;

var firstLineIdx  = 0;
var lines         = [];
var longest       = 0;
var output        = '';
var longestIndent = 0;

var getIndent = function (line) {
  var word = line.match(/([^\s])/);
  if (!word || !word.length) { return 0; }
  return line.indexOf(word[1]);
};

var getLength = function (line) {
  var len;
  if (typeof line !== 'string') { return 0; }
  len = line.match(wordExp);
  return (len && len.length > 0) ? len[1].length : 0;
};

var getHighest = function (acc, num) {
  return (!acc || num > acc) ? num : acc;
}

var getPaddedLine = function (line, varExpr) {
  if (!varExpr || !varExpr.length) { return line; }
  var res = varExpr;
  var indent = getIndent(line);
  while (res.length + indent <= longest + longestIndent) {
    res += ' ';
  }
  return line.replace(varExpr, res);
};

var removePadding = function (line) {
  if (line.indexOf('{') !== -1) { return line; }
  return line.replace(paddedSymbolExp, symbol)
};

var addPadding = function (line) {
  if (line.indexOf('{') !== -1) { return line; }
  return line.
    replace(spaceExp, getPaddedLine).
    replace(symbolExp, symbol + ' ');
}

var processInput = function (input) {
  lines = input.split('\n');

  if (lines.length) {
    do {
      if (isObjExp.test(lines[firstLineIdx])
          && (lines[firstLineIdx].indexOf('=') === -1
             || (lines[firstLineIdx].indexOf('=') > lines[firstLineIdx].indexOf(':')))) {
        wordExp  = objExp;
        spaceExp = objSpaceExp;
        symbol   = ':';
      }
      else if (varExp.test(lines[firstLineIdx])) {
        wordExp  = varExp;
        spaceExp = varSpaceExp;
        symbol   = '=';
      }
      firstLineIdx++;
    }
    while (!symbol || firstLineIdx < lines.length);

    symbolExp       = new RegExp('(' + symbol + '\\s*)');
    paddedSymbolExp = new RegExp('(\\s*' + symbol + '\\s*)');

    longest = lines.
      map(removePadding).
      map(getLength).
      reduce(getHighest);

    longestIndent = lines.
      map(getIndent).
      reduce(getHighest);

    return lines.
      map(removePadding).
      map(addPadding).
      join('\n');
  }
  return input;
};

process.stdin.on('data', function (input) {
  process.stdout.write(processInput(input));
});