Function getCollection

lib/web/polyfill.js:1480–1571

(C, NAME, methods, commonMethods, isMap, isWeak)

    , tmp   = {};
  
  function getCollection(C, NAME, methods, commonMethods, isMap, isWeak){
    var ADDER = isMap ? 'set' : 'add'
      , proto = C && C[PROTOTYPE]
      , O     = {};
    function initFromIterable(that, iterable){
      if(iterable != undefined)forOf(iterable, isMap, that[ADDER], that);
      return that;
    }
    function fixSVZ(key, chain){
      var method = proto[key];
      if(framework)proto[key] = function(a, b){
        var result = method.call(this, a === 0 ? 0 : a, b);
        return chain ? this : result;
      };
    }
    if(!isNative(C) || !(isWeak || (!BUGGY_ITERATORS && has(proto, FOR_EACH) && has(proto, 'entries')))){
      // create collection constructor
      C = isWeak
        ? function(iterable){
            assertInstance(this, C, NAME);
            set(this, UID, uid++);
            initFromIterable(this, iterable);
          }
        : function(iterable){
            var that = this;
            assertInstance(that, C, NAME);
            set(that, O1, create(null));
            set(that, SIZE, 0);
            set(that, LAST, undefined);
            set(that, FIRST, undefined);
            initFromIterable(that, iterable);
          };
      assignHidden(assignHidden(C[PROTOTYPE], methods), commonMethods);
      isWeak || !DESC || defineProperty(C[PROTOTYPE], 'size', {get: function(){
        return assertDefined(this[SIZE]);
      }});
    } else {
      var Native = C
        , inst   = new C
        , chain  = inst[ADDER](isWeak ? {} : -0, 1)
        , buggyZero;
      // wrap to init collections from iterable
      if(checkDangerIterClosing(function(O){ new C(O) })){
        C = function(iterable){
          assertInstance(this, C, NAME);
          return initFromIterable(new Native, iterable);
        };
        C[PROTOTYPE] = proto;
        if(framework)proto[CONSTRUCTOR] = C;
      }
      isWeak || inst[FOR_EACH](function(val, key){
        buggyZero = 1 / key === -Infinity;
      });
      // fix converting -0 key to +0
      if(buggyZero){
        fixSVZ('delete');
        fixSVZ('has');
        isMap && fixSVZ('get');