equal.js

equal.js

//
// A basic function to check whether two values are equal, in the intuitive sense.
//
function equal(a, b) {
  if (a !== null && a !== undefined && b !== null && b !== undefined) {
    if (a.length !== b.length) return false; 
    if (a !== a.toString() && b !== b.toString()) {
      for (var i in a) { if (!equal(a[i],b[i])) return false; }
      for (var i in b) { if (!equal(a[i],b[i])) return false; }
    }  
  }
  return (a+'') === (b+'');
}

//
// A basic function to check whether b is a subset of a..
//
function subset(a, b) {
  if (a !== null && a !== undefined && b !== null && b !== undefined) {
    if (a.length !== b.length) return false; 
    if (b !== b.toString()) {
      for (var i in b) { if (!equal(a[i],b[i])) return false; }
    }  
  }
  return (a+'') === (b+'');
}


//
// The use cases. 
//
if (equal(124,124)) ; else throw '';
if (equal(124,125)) throw '';
if (equal('a','a')) ; else throw '';
if (equal('a','b')) throw '';
if (equal([],[]))   ; else throw '';
if (equal([],[1]))  throw '';  
if (equal([1,2,3,4],[1,2,3])) throw ''; 
if (equal([1,2,3],[1,2,3,4])) throw ''; 
if (equal({a:1},{a:1})) ; else throw ''; 
if (equal({a:1,b:1},{a:1})) throw '';             
if (equal({a:1,b:2,c:3,d:4},{a:1,c:3})) throw '';

if (equal({a:1,b:1},{a:2})) throw ''; 
if (equal(null,undefined))  throw ''; 
if (equal(null,[])) throw ''; 
if (equal(null,{})) throw ''; 
if (equal(null,0))  throw ''; 
if (equal(undefined,[])) throw ''; 
if (equal(undefined,{})) throw ''; 
if (equal(undefined,0))  throw '';  
if (equal({},[])) throw ''; 
if (equal([],{})) throw ''; 
if (equal([1],{0:1})) throw ''; 
if (equal({0:1},[1])) throw ''; 
if (equal('aaa',new String('aaa'))) ; else throw ''; 
if (equal(123,  new Number(123)))   ; else throw '';