old_contents: var regret = require('regret');
  
  regret.add(
    'ctimeV2', // ctime
    /\w{3} \w{3} (?: \d|\d{2}) \d{2}:\d{2}:\d{2}.\d{3}/,
    'Wed Mar  2 14:42:31.000'
  );
  
  regret.add(
    'ctimeV1', // ctime-pre2.4
    /\w{3} \w{3} (?: \d|\d{2}) \d{2}:\d{2}:\d{2}/,
    'Wed Mar  2 14:42:31'
  );
  
  regret.add(
    'iso8601_local',
    /\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}[+-]\d{4}/,
    '2014-02-13T18:00:04.709-0500'
  );
  
  regret.add(
    'iso8601_utc',
    /\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z/,
    '1970-01-01T00:00:00.000Z'
  );
  
  regret.add(
    'timestamp',
    /({{ctimeV1}}|{{ctimeV2}}|{{iso8601_local}}|{{iso8601_utc}})/
  );
  
  regret.add(
    'mongodb.log', 
    /^{{timestamp}} \[(\w+)\] (.*)/,
    '2014-02-13T18:00:04.709-0500 [initandlisten] db version v2.5.6-pre-',
    ['date', 'name', 'message']
  );
  
  regret.add(
    'mongodb.logshutdown', 
    /(\w+)\: (.*)/,
    'dbexit: really exiting now', 
    ['name', 'message']
  );
  
  module.exports = regret;
new_contents: var regret = require('regret');
  
  regret.add(
    'ctime', // covers ctime and ctime-pre2.4
    /\w{3} \w{3} (?: \d|\d{2}) \d{2}:\d{2}:\d{2}(?:|.\d{3})/,
    'Wed Mar  2 14:42:31.000'
  );
  
  regret.add(
    'iso8601', // covers iso8601-local and iso8601-utc
    /\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}(?:Z|[+-]\d{4})/,
    '2014-02-13T18:00:04.709-0500'
  );
  
  regret.add(
    'mongodb.log', 
    /^({{ctime}}|{{iso8601}}) \[(\w+)\] (.*)/,
    '2014-02-13T18:00:04.709-0500 [initandlisten] db version v2.5.6-pre-',
    ['date', 'name', 'message']
  );
  
  regret.add(
    'mongodb.logshutdown', 
    /(\w+)\: (.*)/,
    'dbexit: really exiting now', 
    ['name', 'message']
  );
  
  module.exports = regret;
subject: consolidate cases further