sliding & windows implementation unification

Author: slowcheetah

packages/core-js/internals/iterator-chunking.js

@@ -0,0 +1,45 @@
+'use strict';
+var anObject = require('../internals/an-object');
+var call = require('../internals/function-call');
+var createIteratorProxy = require('../internals/iterator-create-proxy');
+var createIterResultObject = require('../internals/create-iter-result-object');
+var getIteratorDirect = require('../internals/get-iterator-direct');
+var iteratorClose = require('../internals/iterator-close');
+var uncurryThis = require('../internals/function-uncurry-this');
+
+var $RangeError = RangeError;
+var push = uncurryThis([].push);
+var slice = uncurryThis([].slice);
+
+var IteratorProxy = createIteratorProxy(function () {
+  var iterator = this.iterator;
+  var next = this.next;
+  var buffer = this.buffer;
+  var windowSize = this.windowSize;
+  var extraCondition = this.extraCondition;
+  var result, done;
+  while (true) {
+    result = anObject(call(next, iterator));
+    done = this.done = !!result.done;
+    if (extraCondition && done && buffer.length && buffer.length < windowSize) return createIterResultObject(buffer, false);
+    if (done) return createIterResultObject(undefined, true);
+
+    if (buffer.length === windowSize) this.buffer = buffer = slice(buffer, 1);
+    push(buffer, result.value);
+    if (buffer.length === windowSize) return createIterResultObject(buffer, false);
+  }
+}, false, true);
+
+// `Iterator.prototype.sliding` and `Iterator.prototype.windows` methods
+// https://github.com/tc39/proposal-iterator-chunking
+module.exports = function (windowSize, extraCondition) {
+  var O = anObject(this);
+  if (typeof windowSize != 'number' || !windowSize || windowSize >>> 0 !== windowSize) {
+    return iteratorClose(O, 'throw', new $RangeError('windowSize must be integer in [1, 2^32-1]'));
+  }
+  return new IteratorProxy(getIteratorDirect(O), {
+    windowSize: windowSize,
+    buffer: [],
+    extraCondition: extraCondition
+  });
+};

packages/core-js/modules/esnext.iterator.sliding.js

@@ -1,46 +1,12 @@
 'use strict';
 var $ = require('../internals/export');
-var anObject = require('../internals/an-object');
 var call = require('../internals/function-call');
-var createIteratorProxy = require('../internals/iterator-create-proxy');
-var createIterResultObject = require('../internals/create-iter-result-object');
-var getIteratorDirect = require('../internals/get-iterator-direct');
-var iteratorClose = require('../internals/iterator-close');
-var uncurryThis = require('../internals/function-uncurry-this');
-
-var $RangeError = RangeError;
-var push = uncurryThis([].push);
-var slice = uncurryThis([].slice);
-
-var IteratorProxy = createIteratorProxy(function () {
-  var iterator = this.iterator;
-  var next = this.next;
-  var buffer = this.buffer;
-  var windowSize = this.windowSize;
-  var result, done;
-  while (true) {
-    result = anObject(call(next, iterator));
-    done = this.done = !!result.done;
-    if (done && buffer.length && buffer.length < windowSize) return createIterResultObject(buffer, false);
-    if (done) return createIterResultObject(undefined, true);
-
-    if (buffer.length === windowSize) this.buffer = buffer = slice(buffer, 1);
-    push(buffer, result.value);
-    if (buffer.length === windowSize) return createIterResultObject(buffer, false);
-  }
-}, false, true);
+var implementation = require('../internals/iterator-chunking');
 
 // `Iterator.prototype.sliding` method
 // https://github.com/tc39/proposal-iterator-chunking
 $({ target: 'Iterator', proto: true, real: true, forced: true }, {
   sliding: function sliding(windowSize) {
-    var O = anObject(this);
-    if (typeof windowSize != 'number' || !windowSize || windowSize >>> 0 !== windowSize) {
-      return iteratorClose(O, 'throw', new $RangeError('windowSize must be integer in [1, 2^32-1]'));
-    }
-    return new IteratorProxy(getIteratorDirect(O), {
-      windowSize: windowSize,
-      buffer: []
-    });
+    return call(implementation, this, windowSize, true);
   }
 });

packages/core-js/modules/esnext.iterator.windows.js

@@ -1,44 +1,12 @@
 'use strict';
 var $ = require('../internals/export');
-var anObject = require('../internals/an-object');
 var call = require('../internals/function-call');
-var createIteratorProxy = require('../internals/iterator-create-proxy');
-var getIteratorDirect = require('../internals/get-iterator-direct');
-var iteratorClose = require('../internals/iterator-close');
-var uncurryThis = require('../internals/function-uncurry-this');
-
-var $RangeError = RangeError;
-var push = uncurryThis([].push);
-var slice = uncurryThis([].slice);
-
-var IteratorProxy = createIteratorProxy(function () {
-  var iterator = this.iterator;
-  var next = this.next;
-  var buffer = this.buffer;
-  var windowSize = this.windowSize;
-  var result, done;
-  while (true) {
-    result = anObject(call(next, iterator));
-    done = this.done = !!result.done;
-    if (done) return;
-
-    if (buffer.length === windowSize) this.buffer = buffer = slice(buffer, 1);
-    push(buffer, result.value);
-    if (buffer.length === windowSize) return buffer;
-  }
-});
+var implementation = require('../internals/iterator-chunking');
 
 // `Iterator.prototype.windows` method
 // https://github.com/tc39/proposal-iterator-chunking
 $({ target: 'Iterator', proto: true, real: true, forced: true }, {
   windows: function windows(windowSize) {
-    var O = anObject(this);
-    if (typeof windowSize != 'number' || !windowSize || windowSize >>> 0 !== windowSize) {
-      return iteratorClose(O, 'throw', new $RangeError('windowSize must be integer in [1, 2^32-1]'));
-    }
-    return new IteratorProxy(getIteratorDirect(O), {
-      windowSize: windowSize,
-      buffer: []
-    });
+    return call(implementation, this, windowSize, false);
   }
 });