Simple each( obj | array ) function

each.js

// each( collection { obj || array }, callback, [ context ] )
// iterates over a collection, runs callback with either collection or optional context as value of 'this'
// 
// callback sent the following arguments:
// * current item value
// * index or key
// * collection

( function( global ) {

function isObject( obj ) {
  return Object.prototype.toString.call( obj ) === '[object Object]';
}

function each( obj, callback, context ) {
  var i = -1;

  if ( isObject( obj ) ) {
    for ( key in obj ) {
      if ( obj.hasOwnProperty( key ) ) {
        current = obj[key];
        if ( callback.call( context || obj, current, key, obj ) === false ) { break; }
      }
    }
  }
  else {
    try {
      for ( ; obj[++i]; ) {
        current = obj[i];
        if ( callback.call( context || obj, current, i, obj ) === false ) { break; }
      }      
    }
    catch(e) {
      throw new Error('Unable to iterate over ' + obj + ' ' + e.message );
    }
  }

}

global.each = each;

// pass-in eg library.util etc instead of this if not desired in global namespace
}( this ) );