LibTest/collection/LinkedList/takeWhile_A01_t01.dart

/*
 * Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 * for details. All rights reserved. Use of this source code is governed by a
 * BSD-style license that can be found in the LICENSE file.
 */
/**
 * @assertion Iterable<E> takeWhile(bool test(E value))
 * Returns an Iterable that stops once test is not satisfied anymore.
 * @description Checks that all first elements that satisfy test are retained, and
 * elements after that, are skipped.
 * @author kaigorodov
 */
import "dart:collection";
import "../../../Utils/expect.dart";
import "LinkedList.lib.dart";

void check(LinkedList<MyLinkedListEntry<int>> a0, bool test(int element)) {
  bool test2(MyLinkedListEntry<int> entry)=>test(entry.value);
  
  Iterator<MyLinkedListEntry<int>> it0=a0.iterator;
  Iterable<MyLinkedListEntry<int>> a=a0.takeWhile(test2);
  Iterator<MyLinkedListEntry<int>> it=a.iterator;
  
  // check that the beginning of a0 is identical to a
  bool hasNext0=it0.moveNext();
  int len=0;
  while (it.moveNext()) {
    Expect.isTrue(test2(it0.current));
    Expect.equals(it0.current, it.current);
    len++;
    hasNext0=it0.moveNext();
  }
  Expect.equals(a.length, len);

  // count the rest
  int skipCount=0;
  while (hasNext0) {
    skipCount++;
    hasNext0=it0.moveNext();
  }

  Expect.equals(a0.length, len+skipCount);
}

main() {
  LinkedList<MyLinkedListEntry<int>> a0=toLinkedList([1,3,7,4,5,6,1]);
  check(a0, (int element)=>element==1);
  check(a0, (int element)=>true);
  check(a0, (int element)=>false);
  check(a0, (int element)=>element>4);
  check(a0, (int element)=>element<4);
  check(a0, (int element)=>element==4);
}