'use strict'; 
module.exports = function equal(a, b){ 
if (a === b) return true ; 
if (a && b && typeof a == 'object' && typeof b == 'object') { 
if (a.constructor !== b.constructor) return false ; 
var length, i, keys; 
if (Array.isArray(a)) { 
length = _AN_Read_length('length', a); 
if (length != _AN_Read_length('length', b)) return false ; 
for (i = length; i--  !== 0; )if (!equal(a[i], b[i])) return false ; 
return true ; 
} 
if (a.constructor === RegExp) return a.source === b.source && a.flags === b.flags; 
if (a.valueOf !== Object.prototype.valueOf) return a.valueOf() === b.valueOf(); 
if (a.toString !== Object.prototype.toString) return a.toString() === b.toString(); 
keys = Object.keys(a); 
length = _AN_Read_length('length', keys); 
if (length !== _AN_Read_length('length', Object.keys(b))) return false ; 
for (i = length; i--  !== 0; )if (!Object.prototype.hasOwnProperty.call(b, keys[i])) return false ; 
for (i = length; i--  !== 0; ){ 
var key = keys[i]; 
if (!equal(a[key], b[key])) return false ; 
} 
return true ; 
} 
return a !== a && b !== b; 
} 
;