2 * Copyright 2015 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #include <glog/logging.h>
18 #include <gtest/gtest.h>
24 #include <folly/FBVector.h>
25 #include <folly/MapUtil.h>
26 #include <folly/Memory.h>
27 #include <folly/dynamic.h>
28 #include <folly/gen/Base.h>
29 #include <folly/experimental/TestUtil.h>
31 using namespace folly::gen;
32 using namespace folly;
33 using std::make_tuple;
39 using std::unique_ptr;
42 #define EXPECT_SAME(A, B) \
43 static_assert(std::is_same<A, B>::value, "Mismatched: " #A ", " #B)
44 EXPECT_SAME(int&&, typename ArgumentReference<int>::type);
45 EXPECT_SAME(int&, typename ArgumentReference<int&>::type);
46 EXPECT_SAME(const int&, typename ArgumentReference<const int&>::type);
47 EXPECT_SAME(const int&, typename ArgumentReference<const int>::type);
50 ostream& operator<<(ostream& os, const set<T>& values) {
51 return os << from(values);
55 ostream& operator<<(ostream& os, const vector<T>& values) {
57 for (auto& value : values) {
58 if (&value != &values.front()) {
66 auto square = [](int x) { return x * x; };
67 auto add = [](int a, int b) { return a + b; };
68 auto multiply = [](int a, int b) { return a * b; };
70 auto product = foldl(1, multiply);
72 template<typename A, typename B>
73 ostream& operator<<(ostream& os, const pair<A, B>& pair) {
74 return os << "(" << pair.first << ", " << pair.second << ")";
78 auto gen = seq(1, 10);
79 EXPECT_EQ(10, gen | count);
80 EXPECT_EQ(5, gen | take(5) | count);
84 auto gen = seq(1, 10);
85 EXPECT_EQ((1 + 10) * 10 / 2, gen | sum);
86 EXPECT_EQ((1 + 5) * 5 / 2, gen | take(5) | sum);
92 gen | [&](int x) { accum += x; };
95 gen | take(3) | [&](int x) { accum2 += x; };
100 auto expected = vector<int>{4, 9, 16};
101 auto gen = from({2, 3, 4}) | map(square);
102 EXPECT_EQ((vector<int>{4, 9, 16}), gen | as<vector>());
103 EXPECT_EQ((vector<int>{4, 9}), gen | take(2) | as<vector>());
108 Counter(int start = 0)
112 int count() const { return c; }
113 int incr() { return ++c; }
115 int& ref() { return c; }
116 const int& ref() const { return c; }
120 auto counters = seq(1, 10) | eachAs<Counter>() | as<vector>();
121 EXPECT_EQ(10 * (1 + 10) / 2,
123 | member(&Counter::count)
125 EXPECT_EQ(10 * (1 + 10) / 2,
128 | member(&Counter::count)
130 EXPECT_EQ(10 * (2 + 11) / 2,
132 | member(&Counter::incr)
134 EXPECT_EQ(10 * (3 + 12) / 2,
137 | member(&Counter::incr)
139 EXPECT_EQ(10 * (3 + 12) / 2,
141 | member(&Counter::count)
144 // type-verifications
145 auto m = empty<Counter&>();
146 auto c = empty<const Counter&>();
147 m | member(&Counter::incr) | assert_type<int&&>();
148 m | member(&Counter::count) | assert_type<int&&>();
149 m | member(&Counter::count) | assert_type<int&&>();
150 m | member<Const>(&Counter::ref) | assert_type<const int&>();
151 m | member<Mutable>(&Counter::ref) | assert_type<int&>();
152 c | member<Const>(&Counter::ref) | assert_type<const int&>();
157 X() : a(2), b(3), c(4), d(b) {}
162 int& d; // can't access this with a field pointer.
165 std::vector<X> xs(1);
166 EXPECT_EQ(2, from(xs)
169 EXPECT_EQ(3, from(xs)
172 EXPECT_EQ(4, from(xs)
175 EXPECT_EQ(2, seq(&xs[0], &xs[0])
179 empty<X&>() | field(&X::a) | assert_type<const int&>();
180 empty<X*>() | field(&X::a) | assert_type<const int&>();
181 empty<X&>() | field(&X::b) | assert_type<int&>();
182 empty<X*>() | field(&X::b) | assert_type<int&>();
183 empty<X&>() | field(&X::c) | assert_type<int&>();
184 empty<X*>() | field(&X::c) | assert_type<int&>();
186 empty<X&&>() | field(&X::a) | assert_type<const int&&>();
187 empty<X&&>() | field(&X::b) | assert_type<int&&>();
188 empty<X&&>() | field(&X::c) | assert_type<int&&>();
189 // references don't imply ownership so they're not moved
191 empty<const X&>() | field(&X::a) | assert_type<const int&>();
192 empty<const X*>() | field(&X::a) | assert_type<const int&>();
193 empty<const X&>() | field(&X::b) | assert_type<const int&>();
194 empty<const X*>() | field(&X::b) | assert_type<const int&>();
195 // 'mutable' has no effect on field pointers, by C++ spec
196 empty<const X&>() | field(&X::c) | assert_type<const int&>();
197 empty<const X*>() | field(&X::c) | assert_type<const int&>();
199 // can't form pointer-to-reference field: empty<X&>() | field(&X::d)
203 // cover the fenceposts of the loop unrolling
204 for (int n = 1; n < 100; ++n) {
205 EXPECT_EQ(n, seq(1, n) | count);
206 EXPECT_EQ(n + 1, seq(1) | take(n + 1) | count);
210 TEST(Gen, SeqWithStep) {
211 EXPECT_EQ(75, seq(5, 25, 5) | sum);
214 TEST(Gen, SeqWithStepArray) {
215 const std::array<int, 6> arr{{1, 2, 3, 4, 5, 6}};
216 EXPECT_EQ(9, seq(&arr[0], &arr[5], 2)
217 | map([](const int *i) { return *i; })
222 // cover the fenceposts of the loop unrolling
223 for (int n = 1; n < 100; ++n) {
224 EXPECT_EQ(gen::range(0, n) | count, n);
228 TEST(Gen, RangeWithStep) {
229 EXPECT_EQ(50, range(5, 25, 5) | sum);
232 TEST(Gen, FromIterators) {
233 vector<int> source {2, 3, 5, 7, 11};
234 auto gen = from(folly::range(source.begin() + 1, source.end() - 1));
235 EXPECT_EQ(3 * 5 * 7, gen | product);
239 auto source = seq(0, 10)
240 | map([](int i) { return std::make_pair(i, i * i); })
241 | as<std::map<int, int>>();
242 auto gen = fromConst(source)
243 | map([&](const std::pair<const int, int>& p) {
244 return p.second - p.first;
246 EXPECT_EQ(330, gen | sum);
250 const auto expected = vector<int>{1, 2, 4, 5, 7, 8};
253 | filter([](int x) { return x % 3; })
255 EXPECT_EQ(expected, actual);
258 TEST(Gen, FilterDefault) {
260 // Default filter should remove 0s
261 const auto expected = vector<int>{1, 1, 2, 3};
263 from({0, 1, 1, 0, 2, 3, 0})
266 EXPECT_EQ(expected, actual);
269 // Default filter should remove nullptrs
273 const auto expected = vector<int*>{&a, &b, &c};
275 from({(int*)nullptr, &a, &b, &c, (int*)nullptr})
278 EXPECT_EQ(expected, actual);
281 // Default filter on Optionals should remove folly::null
282 const auto expected =
283 vector<Optional<int>>{Optional<int>(5), Optional<int>(0)};
285 from({Optional<int>(5), Optional<int>(), Optional<int>(0)})
288 EXPECT_EQ(expected, actual);
292 TEST(Gen, Contains) {
297 EXPECT_TRUE(gen | contains(49));
298 EXPECT_FALSE(gen | contains(50));
302 seq(1) // infinite, to prove laziness
304 | eachTo<std::string>();
306 // std::string gen, const char* needle
307 EXPECT_TRUE(gen | take(9999) | contains("49"));
313 auto expected = vector<int>{1, 4, 9, 16};
316 | mapped([](int x) { return x * x; })
319 EXPECT_EQ(expected, actual);
322 auto expected = vector<int>{ 0, 1, 4, 5, 8 };
324 = ((seq(0) | take(2)) +
329 EXPECT_EQ(expected, actual);
332 auto expected = vector<int>{ 0, 1, 4, 5, 8 };
336 return seq(i * 4) | take(2);
341 EXPECT_EQ(expected, actual);
348 EXPECT_THROW(stride(0), std::invalid_argument);
351 auto expected = vector<int>{1, 2, 3, 4};
356 EXPECT_EQ(expected, actual);
359 auto expected = vector<int>{1, 3, 5, 7};
364 EXPECT_EQ(expected, actual);
367 auto expected = vector<int>{1, 4, 7, 10};
372 EXPECT_EQ(expected, actual);
375 auto expected = vector<int>{1, 3, 5, 7, 9, 1, 4, 7, 10};
377 = ((seq(1, 10) | stride(2)) +
378 (seq(1, 10) | stride(3)))
380 EXPECT_EQ(expected, actual);
382 EXPECT_EQ(500, seq(1) | take(1000) | stride(2) | count);
383 EXPECT_EQ(10, seq(1) | take(1000) | stride(2) | take(10) | count);
387 std::mt19937 rnd(42);
392 std::unordered_map<int,int> hits;
393 const int kNumIters = 80;
394 for (int i = 0; i < kNumIters; i++) {
395 auto vec = sampler | as<vector<int>>();
396 EXPECT_EQ(vec.size(), 50);
397 auto uniq = fromConst(vec) | as<set<int>>();
398 EXPECT_EQ(uniq.size(), vec.size()); // sampling without replacement
404 // In 80 separate samples of our range, we should have seen every value
405 // at least once and no value all 80 times. (The odds of either of those
406 // events is 1/2^80).
407 EXPECT_EQ(hits.size(), 100);
408 for (auto hit: hits) {
409 EXPECT_GT(hit.second, 0);
410 EXPECT_LT(hit.second, kNumIters);
416 EXPECT_EQ((small | sum), 15);
417 EXPECT_EQ((small | take(3) | count), 3);
423 | mapped([](int x) { return x * x; })
426 EXPECT_EQ((vector<int>{25, 36, 49, 64}), gen | as<vector>());
431 auto expected = vector<int>{1, 4, 9, 16};
434 | mapped([](int x) { return x * x; })
435 | until([](int x) { return x > 20; })
437 EXPECT_EQ(expected, actual);
440 auto expected = vector<int>{ 0, 1, 4, 5, 8 };
442 = ((seq(0) | until([](int i) { return i > 1; })) +
443 (seq(4) | until([](int i) { return i > 5; })) +
444 (seq(8) | until([](int i) { return i > 9; })))
445 | until([](int i) { return i > 8; })
447 EXPECT_EQ(expected, actual);
451 auto expected = vector<int>{ 0, 1, 5, 6, 10 };
455 return seq(i * 5) | until([=](int j) { return j > i * 5 + 1; });
458 | until([](int i) { return i > 10; })
460 EXPECT_EQ(expected, actual);
465 TEST(Gen, Composed) {
466 // Operator, Operator
468 filter([](Optional<int>& o) { return o.hasValue(); })
469 | map([](Optional<int>& o) -> int& { return o.value(); });
470 std::vector<Optional<int>> opts {
471 none, 4, none, 6, none
473 EXPECT_EQ(4 * 4 + 6 * 6, from(opts) | valuesOf | map(square) | sum);
475 auto sumOpt = valuesOf | sum;
476 EXPECT_EQ(10, from(opts) | sumOpt);
480 std::vector<int> nums {2, 3, 5, 7};
481 std::map<int, int> mappings { { 3, 9}, {5, 25} };
482 auto gen = from(nums) + (from(mappings) | get<1>());
483 EXPECT_EQ(51, gen | sum);
484 EXPECT_EQ(5, gen | take(2) | sum);
485 EXPECT_EQ(26, gen | take(5) | sum);
489 std::vector<std::vector<int>> nums {{2, 3}, {5, 7}};
490 auto gen = from(nums) | rconcat;
491 EXPECT_EQ(17, gen | sum);
492 EXPECT_EQ(10, gen | take(3) | sum);
495 TEST(Gen, ConcatGen) {
496 auto gen = seq(1, 10)
497 | map([](int i) { return seq(1, i); })
499 EXPECT_EQ(220, gen | sum);
500 EXPECT_EQ(10, gen | take(6) | sum);
503 TEST(Gen, ConcatAlt) {
504 std::vector<std::vector<int>> nums {{2, 3}, {5, 7}};
505 auto actual = from(nums)
506 | map([](std::vector<int>& v) { return from(v); })
510 EXPECT_EQ(expected, actual);
514 auto expected = vector<int>{0, 3, 5, 6, 7, 8, 9};
516 from({8, 6, 7, 5, 3, 0, 9})
519 EXPECT_EQ(expected, actual);
522 TEST(Gen, OrderMoved) {
523 auto expected = vector<int>{0, 9, 25, 36, 49, 64, 81};
525 from({8, 6, 7, 5, 3, 0, 9})
530 EXPECT_EQ(expected, actual);
533 TEST(Gen, OrderTake) {
534 auto expected = vector<int>{9, 8, 7};
536 from({8, 6, 7, 5, 3, 0, 9})
537 | orderByDescending(square)
540 EXPECT_EQ(expected, actual);
543 TEST(Gen, Distinct) {
544 auto expected = vector<int>{3, 1, 2};
546 from({3, 1, 3, 2, 1, 2, 3})
549 EXPECT_EQ(expected, actual);
552 TEST(Gen, DistinctBy) { // 0 1 4 9 6 5 6 9 4 1 0
553 auto expected = vector<int>{0, 1, 2, 3, 4, 5};
556 | distinctBy([](int i) { return i * i % 10; })
558 EXPECT_EQ(expected, actual);
561 TEST(Gen, DistinctMove) { // 0 1 4 9 6 5 6 9 4 1 0
562 auto expected = vector<int>{0, 1, 2, 3, 4, 5};
565 | mapped([](int i) { return std::unique_ptr<int>(new int(i)); })
566 // see comment below about selector parameters for Distinct
567 | distinctBy([](const std::unique_ptr<int>& pi) { return *pi * *pi % 10; })
568 | mapped([](std::unique_ptr<int> pi) { return *pi; })
571 // NOTE(tjackson): the following line intentionally doesn't work:
572 // | distinctBy([](std::unique_ptr<int> pi) { return *pi * *pi % 10; })
573 // This is because distinctBy because the selector intentionally requires a
574 // const reference. If it required a move-reference, the value might get
575 // gutted by the selector before said value could be passed to downstream
577 EXPECT_EQ(expected, actual);
581 EXPECT_EQ(7, seq(1, 10)
582 | minBy([](int i) -> double {
589 auto gen = from({"three", "eleven", "four"});
591 EXPECT_EQ("eleven", gen | maxBy(&strlen));
595 string expected = "facebook";
596 string actual = "face";
597 from(StringPiece("book")) | appendTo(actual);
598 EXPECT_EQ(expected, actual);
601 TEST(Gen, FromRValue) {
603 // AFAICT The C++ Standard does not specify what happens to the rvalue
604 // reference of a std::vector when it is used as the 'other' for an rvalue
605 // constructor. Use fbvector because we're sure its size will be zero in
607 fbvector<int> v({1,2,3,4});
609 EXPECT_EQ(v.size(), 4); // ensure that the lvalue version was called!
610 auto expected = 1 * 2 * 3 * 4;
611 EXPECT_EQ(expected, q1 | product);
613 auto q2 = from(std::move(v));
614 EXPECT_EQ(v.size(), 0); // ensure that rvalue version was called
615 EXPECT_EQ(expected, q2 | product);
619 auto q = from([] {return vector<int>({3,7,5}); }());
620 EXPECT_EQ(expected, q | max);
623 for (auto size: {5, 1024, 16384, 1<<20}) {
624 auto q1 = from(vector<int>(size, 2));
625 auto q2 = from(vector<int>(size, 3));
626 // If the rvalue specialization is broken/gone, then the compiler will
627 // (disgustingly!) just store a *reference* to the temporary object,
628 // which is bad. Try to catch this by allocating two temporary vectors
629 // of the same size, so that they'll probably use the same underlying
630 // buffer if q1's vector is destructed before q2's vector is constructed.
631 EXPECT_EQ(size * 2 + size * 3, (q1 | sum) + (q2 | sum));
635 auto q = from(set<int>{1,2,3,2,1});
636 EXPECT_EQ(q | sum, 6);
641 auto expected = vector<int>{5, 6, 4, 7, 3, 8, 2, 9, 1, 10};
644 | orderBy([](int x) { return (5.1 - x) * (5.1 - x); })
646 EXPECT_EQ(expected, actual);
648 expected = seq(1, 10) | as<vector>();
651 | map([] (int x) { return 11 - x; })
654 EXPECT_EQ(expected, actual);
658 int expected = 2 * 3 * 4 * 5;
661 | foldl(1, multiply);
662 EXPECT_EQ(expected, actual);
666 int expected = 2 + 3 + 4 + 5;
667 auto actual = seq(2, 5) | reduce(add);
668 EXPECT_EQ(expected, actual);
671 TEST(Gen, ReduceBad) {
672 auto gen = seq(1) | take(0);
682 std::vector<unique_ptr<int>> ptrs;
683 ptrs.emplace_back(new int(1));
684 EXPECT_NE(ptrs.front().get(), nullptr);
685 auto ptrs2 = from(ptrs) | move | as<vector>();
686 EXPECT_EQ(ptrs.front().get(), nullptr);
687 EXPECT_EQ(**ptrs2.data(), 1);
693 | filter([](int x) { return x > 3; });
694 EXPECT_EQ(4, gen | first);
697 TEST(Gen, FromCopy) {
698 vector<int> v {3, 5};
700 auto copy = fromCopy(v);
701 EXPECT_EQ(8, src | sum);
702 EXPECT_EQ(8, copy | sum);
704 EXPECT_EQ(10, src | sum);
705 EXPECT_EQ(8, copy | sum);
709 std::map<int, int> pairs {
715 auto pairSrc = from(pairs);
716 auto keys = pairSrc | get<0>();
717 auto values = pairSrc | get<1>();
718 EXPECT_EQ(10, keys | sum);
719 EXPECT_EQ(30, values | sum);
720 EXPECT_EQ(30, keys | map(square) | sum);
722 EXPECT_EQ(15, keys | sum);
723 EXPECT_EQ(55, values | sum);
725 vector<tuple<int, int, int>> tuples {
728 make_tuple(3, 9, 27),
730 EXPECT_EQ(36, from(tuples) | get<2>() | sum);
734 EXPECT_TRUE(seq(0) | any);
735 EXPECT_TRUE(seq(0, 1) | any);
736 EXPECT_TRUE(seq(0, 10) | any([](int i) { return i == 7; }));
737 EXPECT_FALSE(seq(0, 10) | any([](int i) { return i == 11; }));
739 EXPECT_TRUE(from({1}) | any);
740 EXPECT_FALSE(gen::range(0, 0) | any);
741 EXPECT_FALSE(from({1}) | take(0) | any);
745 EXPECT_TRUE(seq(0, 10) | all([](int i) { return i < 11; }));
746 EXPECT_FALSE(seq(0, 10) | all([](int i) { return i < 5; }));
747 EXPECT_FALSE(seq(0) | take(9999) | all([](int i) { return i < 10; }));
749 // empty lists satisfies all
750 EXPECT_TRUE(seq(0) | take(0) | all([](int i) { return i < 50; }));
751 EXPECT_TRUE(seq(0) | take(0) | all([](int i) { return i > 50; }));
754 TEST(Gen, Yielders) {
755 auto gen = GENERATOR(int) {
756 for (int i = 1; i <= 5; ++i) {
760 for (int i = 3; ; ++i) {
764 vector<int> expected {
765 1, 2, 3, 4, 5, 7, 9, 16, 25
767 EXPECT_EQ(expected, gen | take(9) | as<vector>());
770 TEST(Gen, NestedYield) {
771 auto nums = GENERATOR(int) {
772 for (int i = 1; ; ++i) {
776 auto gen = GENERATOR(int) {
777 nums | take(10) | yield;
778 seq(1, 5) | [&](int i) {
782 EXPECT_EQ(70, gen | sum);
785 TEST(Gen, MapYielders) {
788 return GENERATOR(int) {
790 for (i = 1; i < n; ++i)
797 vector<int> expected {
802 1, 2, 3, 4, 5, 4, 3, 2, 1,
804 EXPECT_EQ(expected, gen | as<vector>());
807 TEST(Gen, VirtualGen) {
808 VirtualGen<int> v(seq(1, 10));
809 EXPECT_EQ(55, v | sum);
811 EXPECT_EQ(385, v | sum);
813 EXPECT_EQ(55, v | sum);
814 EXPECT_EQ(30, v | take(4) | sum);
818 TEST(Gen, CustomType) {
822 auto gen = from({Foo{2}, Foo{3}})
823 | map([](const Foo& f) { return f.y; });
824 EXPECT_EQ(5, gen | sum);
827 TEST(Gen, NoNeedlessCopies) {
829 | map([](int x) { return unique_ptr<int>(new int(x)); })
830 | map([](unique_ptr<int> p) { return p; })
831 | map([](unique_ptr<int>&& p) { return std::move(p); })
832 | map([](const unique_ptr<int>& p) { return *p; });
833 EXPECT_EQ(15, gen | sum);
834 EXPECT_EQ(6, gen | take(3) | sum);
839 class TestIntSeq : public GenImpl<int, TestIntSeq> {
843 template <class Body>
844 bool apply(Body&& body) const {
845 for (int i = 1; i < 6; ++i) {
853 TestIntSeq(TestIntSeq&&) noexcept = default;
854 TestIntSeq& operator=(TestIntSeq&&) noexcept = default;
855 TestIntSeq(const TestIntSeq&) = delete;
856 TestIntSeq& operator=(const TestIntSeq&) = delete;
861 TEST(Gen, NoGeneratorCopies) {
862 EXPECT_EQ(15, TestIntSeq() | sum);
863 auto x = TestIntSeq() | take(3);
864 EXPECT_EQ(6, std::move(x) | sum);
867 TEST(Gen, FromArray) {
868 int source[] = {2, 3, 5, 7};
869 auto gen = from(source);
870 EXPECT_EQ(2 * 3 * 5 * 7, gen | product);
873 TEST(Gen, FromStdArray) {
874 std::array<int,4> source {{2, 3, 5, 7}};
875 auto gen = from(source);
876 EXPECT_EQ(2 * 3 * 5 * 7, gen | product);
879 TEST(Gen, StringConcat) {
880 auto gen = seq(1, 10)
883 EXPECT_EQ("12345678910", gen | as<string>());
891 CopyCounter() : copies(0), moves(0) {
895 CopyCounter(CopyCounter&& source) noexcept {
896 *this = std::move(source);
900 CopyCounter(const CopyCounter& source) {
909 CopyCounter& operator=(const CopyCounter& source) {
910 this->copies = source.copies + 1;
911 this->moves = source.moves;
915 CopyCounter& operator=(CopyCounter&& source) {
916 this->copies = source.copies;
917 this->moves = source.moves + 1;
922 int CopyCounter::alive = 0;
924 TEST(Gen, CopyCount) {
925 vector<CopyCounter> originals;
926 originals.emplace_back();
927 EXPECT_EQ(1, originals.size());
928 EXPECT_EQ(0, originals.back().copies);
930 vector<CopyCounter> copies = from(originals) | as<vector>();
931 EXPECT_EQ(1, copies.back().copies);
932 EXPECT_EQ(0, copies.back().moves);
934 vector<CopyCounter> moves = from(originals) | move | as<vector>();
935 EXPECT_EQ(0, moves.back().copies);
936 EXPECT_EQ(1, moves.back().moves);
939 // test dynamics with various layers of nested arrays.
941 dynamic array1 = {1, 2};
942 EXPECT_EQ(dynamic(3), from(array1) | sum);
943 dynamic array2 = {{1}, {1, 2}};
944 EXPECT_EQ(dynamic(4), from(array2) | rconcat | sum);
945 dynamic array3 = {{{1}}, {{1}, {1, 2}}};
946 EXPECT_EQ(dynamic(5), from(array3) | rconcat | rconcat | sum);
949 TEST(Gen, DynamicObject) {
950 const dynamic obj = dynamic::object(1, 2)(3, 4);
951 EXPECT_EQ(dynamic(4), from(obj.keys()) | sum);
952 EXPECT_EQ(dynamic(6), from(obj.values()) | sum);
953 EXPECT_EQ(dynamic(4), from(obj.items()) | get<0>() | sum);
954 EXPECT_EQ(dynamic(6), from(obj.items()) | get<1>() | sum);
958 auto s = from({7, 6, 5, 4, 3}) | as<set<int>>();
959 EXPECT_EQ(s.size(), 5);
965 auto s = from({1, 2});
966 EXPECT_EQ((vector<int> { 1, 2, 1, 2, 1 }),
967 s | cycle | take(5) | as<vector>());
970 auto s = from({1, 2});
971 EXPECT_EQ((vector<int> { 1, 2, 1, 2 }),
972 s | cycle(2) | as<vector>());
975 auto s = from({1, 2, 3});
976 EXPECT_EQ((vector<int> { 1, 2, 1, 2, 1 }),
977 s | take(2) | cycle | take(5) | as<vector>());
980 auto s = empty<int>();
981 EXPECT_EQ((vector<int> { }),
982 s | cycle | take(4) | as<vector>());
986 int* pcount = &count;
987 auto countdown = GENERATOR(int) {
988 ASSERT_GE(*pcount, 0)
989 << "Cycle should have stopped when it didnt' get values!";
990 for (int i = 1; i <= *pcount; ++i) {
996 EXPECT_EQ((vector<int> { 1, 2, 3, 1, 2, 1}),
997 s | cycle | as<vector>());
1001 TEST(Gen, Dereference) {
1003 const int x = 4, y = 2;
1004 auto s = from(std::initializer_list<const int*>({&x, nullptr, &y}));
1005 EXPECT_EQ(6, s | dereference | sum);
1008 vector<int> a { 1, 2 };
1009 vector<int> b { 3, 4 };
1010 vector<vector<int>*> pv { &a, nullptr, &b };
1013 | [&](vector<int>& v) {
1016 EXPECT_EQ(3, a.size());
1017 EXPECT_EQ(3, b.size());
1018 EXPECT_EQ(5, a.back());
1019 EXPECT_EQ(5, b.back());
1022 vector<std::map<int, int>> maps {
1039 | map([](std::map<int, int>& m) {
1040 return get_ptr(m, 3);
1046 vector<unique_ptr<int>> ups;
1047 ups.emplace_back(new int(3));
1049 ups.emplace_back(new int(7));
1050 EXPECT_EQ(10, from(ups) | dereference | sum);
1051 EXPECT_EQ(10, from(ups) | move | dereference | sum);
1055 TEST(Gen, Indirect) {
1057 EXPECT_EQ(&vs[0], from(vs) | indirect | first);
1061 using std::runtime_error;
1062 EXPECT_THROW(from({"1", "a", "3"})
1067 from({"1", "a", "3"})
1068 | guard<runtime_error>([](runtime_error&, const char*) {
1069 return true; // continue
1074 from({"1", "a", "3"})
1075 | guard<runtime_error>([](runtime_error&, const char*) {
1076 return false; // break
1080 EXPECT_THROW(from({"1", "a", "3"})
1081 | guard<runtime_error>([](runtime_error&, const char* v) {
1093 EXPECT_EQ((vector<vector<int>> { {1} }),
1094 seq(1, 1) | batch(5) | as<vector>());
1095 EXPECT_EQ((vector<vector<int>> { {1, 2, 3}, {4, 5, 6}, {7, 8, 9}, {10, 11} }),
1096 seq(1, 11) | batch(3) | as<vector>());
1097 EXPECT_THROW(seq(1, 1) | batch(0) | as<vector>(),
1098 std::invalid_argument);
1101 TEST(Gen, BatchMove) {
1102 auto expected = vector<vector<int>>{ {0, 1}, {2, 3}, {4} };
1105 | mapped([](int i) { return std::unique_ptr<int>(new int(i)); })
1107 | mapped([](std::vector<std::unique_ptr<int>>& pVector) {
1108 std::vector<int> iVector;
1109 for (const auto& p : pVector) {
1110 iVector.push_back(*p);
1115 EXPECT_EQ(expected, actual);
1122 EXPECT_EQ(&x, j | indirect | first);
1124 EXPECT_EQ(4, j | first);
1130 EXPECT_EQ(&x, j | indirect | first);
1132 EXPECT_EQ(5, j | first);
1136 auto j = just(std::move(x));
1137 EXPECT_NE(&x, j | indirect | first);
1139 EXPECT_EQ(3, j | first);
1143 TEST(Gen, GroupBy) {
1144 vector<string> strs{"zero", "one", "two", "three", "four",
1145 "five", "six", "seven", "eight", "nine"};
1147 auto gb = from(strs) | groupBy([](const string& str) { return str.size(); });
1149 EXPECT_EQ(10, gb | mapOp(count) | sum);
1150 EXPECT_EQ(3, gb | count);
1152 vector<string> mode{"zero", "four", "five", "nine"};
1155 gb | maxBy([](const Group<size_t, string>& g) { return g.size(); })
1158 vector<string> largest{"three", "seven", "eight"};
1161 gb | maxBy([](const Group<size_t, string>& g) { return g.key(); })
1165 int main(int argc, char *argv[]) {
1166 testing::InitGoogleTest(&argc, argv);
1167 gflags::ParseCommandLineFlags(&argc, &argv, true);
1168 return RUN_ALL_TESTS();