function parseJSON(input, callback) {
  var error
  var result
  try {
    result = JSON.parse(input) }
  catch (e) {
    error = e }
  callback(error, result) }
function parseJSON(input, callback) {
  var error
  var result
  try {
    result = JSON.parse(input) }
  catch (e) {
    error = e }
  callback(error, result) }
function parseJSON ( input , callback ) { var error var result try { result = JSON . parse ( input ) } catch ( e ) { error = e } callback ( error , result ) }
JSON.parse, wrapped to take an errback.
JSON . parse wrapped to take an errback .