2 * Copyright 2016 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, FilterSink) {
295 | map([](int x) { return vector<int>{x}; })
296 | filter([](vector<int> v) { return !v.empty(); })
298 EXPECT_FALSE(from(actual) | rconcat | isEmpty);
301 TEST(Gen, Contains) {
306 EXPECT_TRUE(gen | contains(49));
307 EXPECT_FALSE(gen | contains(50));
311 seq(1) // infinite, to prove laziness
313 | eachTo<std::string>();
315 // std::string gen, const char* needle
316 EXPECT_TRUE(gen | take(9999) | contains("49"));
322 auto expected = vector<int>{1, 4, 9, 16};
325 | mapped([](int x) { return x * x; })
328 EXPECT_EQ(expected, actual);
331 auto expected = vector<int>{ 0, 1, 4, 5, 8 };
333 = ((seq(0) | take(2)) +
338 EXPECT_EQ(expected, actual);
341 auto expected = vector<int>{ 0, 1, 4, 5, 8 };
345 return seq(i * 4) | take(2);
350 EXPECT_EQ(expected, actual);
355 EXPECT_THROW(take(limit - 6), std::invalid_argument);
362 EXPECT_THROW(stride(0), std::invalid_argument);
365 auto expected = vector<int>{1, 2, 3, 4};
370 EXPECT_EQ(expected, actual);
373 auto expected = vector<int>{1, 3, 5, 7};
378 EXPECT_EQ(expected, actual);
381 auto expected = vector<int>{1, 4, 7, 10};
386 EXPECT_EQ(expected, actual);
389 auto expected = vector<int>{1, 3, 5, 7, 9, 1, 4, 7, 10};
391 = ((seq(1, 10) | stride(2)) +
392 (seq(1, 10) | stride(3)))
394 EXPECT_EQ(expected, actual);
396 EXPECT_EQ(500, seq(1) | take(1000) | stride(2) | count);
397 EXPECT_EQ(10, seq(1) | take(1000) | stride(2) | take(10) | count);
401 std::mt19937 rnd(42);
406 std::unordered_map<int,int> hits;
407 const int kNumIters = 80;
408 for (int i = 0; i < kNumIters; i++) {
409 auto vec = sampler | as<vector<int>>();
410 EXPECT_EQ(vec.size(), 50);
411 auto uniq = fromConst(vec) | as<set<int>>();
412 EXPECT_EQ(uniq.size(), vec.size()); // sampling without replacement
418 // In 80 separate samples of our range, we should have seen every value
419 // at least once and no value all 80 times. (The odds of either of those
420 // events is 1/2^80).
421 EXPECT_EQ(hits.size(), 100);
422 for (auto hit: hits) {
423 EXPECT_GT(hit.second, 0);
424 EXPECT_LT(hit.second, kNumIters);
430 EXPECT_EQ((small | sum), 15);
431 EXPECT_EQ((small | take(3) | count), 3);
437 | mapped([](int x) { return x * x; })
440 EXPECT_EQ((vector<int>{25, 36, 49, 64}), gen | as<vector>());
445 auto expected = vector<int>{1, 4, 9, 16};
448 | mapped([](int x) { return x * x; })
449 | until([](int x) { return x > 20; })
451 EXPECT_EQ(expected, actual);
454 auto expected = vector<int>{ 0, 1, 4, 5, 8 };
456 = ((seq(0) | until([](int i) { return i > 1; })) +
457 (seq(4) | until([](int i) { return i > 5; })) +
458 (seq(8) | until([](int i) { return i > 9; })))
459 | until([](int i) { return i > 8; })
461 EXPECT_EQ(expected, actual);
465 auto expected = vector<int>{ 0, 1, 5, 6, 10 };
469 return seq(i * 5) | until([=](int j) { return j > i * 5 + 1; });
472 | until([](int i) { return i > 10; })
474 EXPECT_EQ(expected, actual);
479 TEST(Gen, Composed) {
480 // Operator, Operator
482 filter([](Optional<int>& o) { return o.hasValue(); })
483 | map([](Optional<int>& o) -> int& { return o.value(); });
484 std::vector<Optional<int>> opts {
485 none, 4, none, 6, none
487 EXPECT_EQ(4 * 4 + 6 * 6, from(opts) | valuesOf | map(square) | sum);
489 auto sumOpt = valuesOf | sum;
490 EXPECT_EQ(10, from(opts) | sumOpt);
494 std::vector<int> nums {2, 3, 5, 7};
495 std::map<int, int> mappings { { 3, 9}, {5, 25} };
496 auto gen = from(nums) + (from(mappings) | get<1>());
497 EXPECT_EQ(51, gen | sum);
498 EXPECT_EQ(5, gen | take(2) | sum);
499 EXPECT_EQ(26, gen | take(5) | sum);
503 std::vector<std::vector<int>> nums {{2, 3}, {5, 7}};
504 auto gen = from(nums) | rconcat;
505 EXPECT_EQ(17, gen | sum);
506 EXPECT_EQ(10, gen | take(3) | sum);
509 TEST(Gen, ConcatGen) {
510 auto gen = seq(1, 10)
511 | map([](int i) { return seq(1, i); })
513 EXPECT_EQ(220, gen | sum);
514 EXPECT_EQ(10, gen | take(6) | sum);
517 TEST(Gen, ConcatAlt) {
518 std::vector<std::vector<int>> nums {{2, 3}, {5, 7}};
519 auto actual = from(nums)
520 | map([](std::vector<int>& v) { return from(v); })
524 EXPECT_EQ(expected, actual);
528 auto expected = vector<int>{0, 3, 5, 6, 7, 8, 9};
530 from({8, 6, 7, 5, 3, 0, 9})
533 EXPECT_EQ(expected, actual);
536 TEST(Gen, OrderMoved) {
537 auto expected = vector<int>{0, 9, 25, 36, 49, 64, 81};
539 from({8, 6, 7, 5, 3, 0, 9})
544 EXPECT_EQ(expected, actual);
547 TEST(Gen, OrderTake) {
548 auto expected = vector<int>{9, 8, 7};
550 from({8, 6, 7, 5, 3, 0, 9})
551 | orderByDescending(square)
554 EXPECT_EQ(expected, actual);
557 TEST(Gen, Distinct) {
558 auto expected = vector<int>{3, 1, 2};
560 from({3, 1, 3, 2, 1, 2, 3})
563 EXPECT_EQ(expected, actual);
566 TEST(Gen, DistinctBy) { // 0 1 4 9 6 5 6 9 4 1 0
567 auto expected = vector<int>{0, 1, 2, 3, 4, 5};
570 | distinctBy([](int i) { return i * i % 10; })
572 EXPECT_EQ(expected, actual);
575 TEST(Gen, DistinctMove) { // 0 1 4 9 6 5 6 9 4 1 0
576 auto expected = vector<int>{0, 1, 2, 3, 4, 5};
579 | mapped([](int i) { return std::unique_ptr<int>(new int(i)); })
580 // see comment below about selector parameters for Distinct
581 | distinctBy([](const std::unique_ptr<int>& pi) { return *pi * *pi % 10; })
582 | mapped([](std::unique_ptr<int> pi) { return *pi; })
585 // NOTE(tjackson): the following line intentionally doesn't work:
586 // | distinctBy([](std::unique_ptr<int> pi) { return *pi * *pi % 10; })
587 // This is because distinctBy because the selector intentionally requires a
588 // const reference. If it required a move-reference, the value might get
589 // gutted by the selector before said value could be passed to downstream
591 EXPECT_EQ(expected, actual);
594 TEST(Gen, DistinctInfinite) {
595 // distinct should be able to handle an infinite sequence, provided that, of
596 // of cource, is it eventually made finite before returning the result.
597 auto expected = seq(0) | take(5) | as<vector>(); // 0 1 2 3 4
600 seq(0) // 0 1 2 3 4 5 6 7 ...
601 | mapped([](int i) { return i / 2; }) // 0 0 1 1 2 2 3 3 ...
602 | distinct // 0 1 2 3 4 5 6 7 ...
603 | take(5) // 0 1 2 3 4
606 EXPECT_EQ(expected, actual);
609 TEST(Gen, DistinctByInfinite) {
610 // Similarly to the DistinctInfinite test case, distinct by should be able to
611 // handle infinite sequences. Note that depending on how many values we take()
612 // at the end, the sequence may infinite loop. This is fine becasue we cannot
613 // solve the halting problem.
614 auto expected = vector<int>{1, 2};
616 seq(1) // 1 2 3 4 5 6 7 8 ...
617 | distinctBy([](int i) { return i % 2; }) // 1 2 (but might by infinite)
620 // Note that if we had take(3), this would infinite loop
622 EXPECT_EQ(expected, actual);
626 EXPECT_EQ(7, seq(1, 10)
627 | minBy([](int i) -> double {
635 auto gen = from({"three", "eleven", "four"});
637 EXPECT_EQ("eleven", gen | maxBy(&strlen) | unwrap);
641 auto odds = seq(2,10) | filter([](int i){ return i % 2; });
643 EXPECT_EQ(3, odds | min);
647 auto odds = seq(2,10) | filter([](int i){ return i % 2; });
649 EXPECT_EQ(9, odds | max);
653 string expected = "facebook";
654 string actual = "face";
655 from(StringPiece("book")) | appendTo(actual);
656 EXPECT_EQ(expected, actual);
659 TEST(Gen, FromRValue) {
661 // AFAICT The C++ Standard does not specify what happens to the rvalue
662 // reference of a std::vector when it is used as the 'other' for an rvalue
663 // constructor. Use fbvector because we're sure its size will be zero in
665 fbvector<int> v({1,2,3,4});
667 EXPECT_EQ(v.size(), 4); // ensure that the lvalue version was called!
668 auto expected = 1 * 2 * 3 * 4;
669 EXPECT_EQ(expected, q1 | product);
671 auto q2 = from(std::move(v));
672 EXPECT_EQ(v.size(), 0); // ensure that rvalue version was called
673 EXPECT_EQ(expected, q2 | product);
677 auto q = from([] {return vector<int>({3,7,5}); }());
678 EXPECT_EQ(expected, q | max);
681 for (auto size: {5, 1024, 16384, 1<<20}) {
682 auto q1 = from(vector<int>(size, 2));
683 auto q2 = from(vector<int>(size, 3));
684 // If the rvalue specialization is broken/gone, then the compiler will
685 // (disgustingly!) just store a *reference* to the temporary object,
686 // which is bad. Try to catch this by allocating two temporary vectors
687 // of the same size, so that they'll probably use the same underlying
688 // buffer if q1's vector is destructed before q2's vector is constructed.
689 EXPECT_EQ(size * 2 + size * 3, (q1 | sum) + (q2 | sum));
693 auto q = from(set<int>{1,2,3,2,1});
694 EXPECT_EQ(q | sum, 6);
699 auto expected = vector<int>{5, 6, 4, 7, 3, 8, 2, 9, 1, 10};
702 | orderBy([](int x) { return (5.1 - x) * (5.1 - x); })
704 EXPECT_EQ(expected, actual);
706 expected = seq(1, 10) | as<vector>();
709 | map([] (int x) { return 11 - x; })
712 EXPECT_EQ(expected, actual);
716 int expected = 2 * 3 * 4 * 5;
719 | foldl(1, multiply);
720 EXPECT_EQ(expected, actual);
724 int expected = 2 + 3 + 4 + 5;
725 auto actual = seq(2, 5) | reduce(add);
726 EXPECT_EQ(expected, actual | unwrap);
729 TEST(Gen, ReduceBad) {
730 auto gen = seq(1) | take(0);
731 auto actual = gen | reduce(add);
732 EXPECT_FALSE(actual); // Empty sequences are okay, they just yeild 'none'
736 std::vector<unique_ptr<int>> ptrs;
737 ptrs.emplace_back(new int(1));
738 EXPECT_NE(ptrs.front().get(), nullptr);
739 auto ptrs2 = from(ptrs) | move | as<vector>();
740 EXPECT_EQ(ptrs.front().get(), nullptr);
741 EXPECT_EQ(**ptrs2.data(), 1);
745 auto gen = seq(0) | filter([](int x) { return x > 3; });
746 EXPECT_EQ(4, gen | first | unwrap);
749 TEST(Gen, FromCopy) {
750 vector<int> v {3, 5};
752 auto copy = fromCopy(v);
753 EXPECT_EQ(8, src | sum);
754 EXPECT_EQ(8, copy | sum);
756 EXPECT_EQ(10, src | sum);
757 EXPECT_EQ(8, copy | sum);
761 std::map<int, int> pairs {
767 auto pairSrc = from(pairs);
768 auto keys = pairSrc | get<0>();
769 auto values = pairSrc | get<1>();
770 EXPECT_EQ(10, keys | sum);
771 EXPECT_EQ(30, values | sum);
772 EXPECT_EQ(30, keys | map(square) | sum);
774 EXPECT_EQ(15, keys | sum);
775 EXPECT_EQ(55, values | sum);
777 vector<tuple<int, int, int>> tuples {
780 make_tuple(3, 9, 27),
782 EXPECT_EQ(36, from(tuples) | get<2>() | sum);
785 TEST(Gen, notEmpty) {
786 EXPECT_TRUE(seq(0, 1) | notEmpty);
787 EXPECT_TRUE(just(1) | notEmpty);
788 EXPECT_FALSE(gen::range(0, 0) | notEmpty);
789 EXPECT_FALSE(from({1}) | take(0) | notEmpty);
793 EXPECT_FALSE(seq(0, 1) | isEmpty);
794 EXPECT_FALSE(just(1) | isEmpty);
795 EXPECT_TRUE(gen::range(0, 0) | isEmpty);
796 EXPECT_TRUE(from({1}) | take(0) | isEmpty);
800 EXPECT_TRUE(seq(0, 10) | any([](int i) { return i == 7; }));
801 EXPECT_FALSE(seq(0, 10) | any([](int i) { return i == 11; }));
805 EXPECT_TRUE(seq(0, 10) | all([](int i) { return i < 11; }));
806 EXPECT_FALSE(seq(0, 10) | all([](int i) { return i < 5; }));
807 EXPECT_FALSE(seq(0) | take(9999) | all([](int i) { return i < 10; }));
809 // empty lists satisfies all
810 EXPECT_TRUE(seq(0) | take(0) | all([](int i) { return i < 50; }));
811 EXPECT_TRUE(seq(0) | take(0) | all([](int i) { return i > 50; }));
814 TEST(Gen, Yielders) {
815 auto gen = GENERATOR(int) {
816 for (int i = 1; i <= 5; ++i) {
820 for (int i = 3; ; ++i) {
824 vector<int> expected {
825 1, 2, 3, 4, 5, 7, 9, 16, 25
827 EXPECT_EQ(expected, gen | take(9) | as<vector>());
830 TEST(Gen, NestedYield) {
831 auto nums = GENERATOR(int) {
832 for (int i = 1; ; ++i) {
836 auto gen = GENERATOR(int) {
837 nums | take(10) | yield;
838 seq(1, 5) | [&](int i) {
842 EXPECT_EQ(70, gen | sum);
845 TEST(Gen, MapYielders) {
848 return GENERATOR(int) {
850 for (i = 1; i < n; ++i)
857 vector<int> expected {
862 1, 2, 3, 4, 5, 4, 3, 2, 1,
864 EXPECT_EQ(expected, gen | as<vector>());
867 TEST(Gen, VirtualGen) {
868 VirtualGen<int> v(seq(1, 10));
869 EXPECT_EQ(55, v | sum);
871 EXPECT_EQ(385, v | sum);
873 EXPECT_EQ(55, v | sum);
874 EXPECT_EQ(30, v | take(4) | sum);
878 TEST(Gen, CustomType) {
882 auto gen = from({Foo{2}, Foo{3}})
883 | map([](const Foo& f) { return f.y; });
884 EXPECT_EQ(5, gen | sum);
887 TEST(Gen, NoNeedlessCopies) {
889 | map([](int x) { return unique_ptr<int>(new int(x)); })
890 | map([](unique_ptr<int> p) { return p; })
891 | map([](unique_ptr<int>&& p) { return std::move(p); })
892 | map([](const unique_ptr<int>& p) { return *p; });
893 EXPECT_EQ(15, gen | sum);
894 EXPECT_EQ(6, gen | take(3) | sum);
899 class TestIntSeq : public GenImpl<int, TestIntSeq> {
903 template <class Body>
904 bool apply(Body&& body) const {
905 for (int i = 1; i < 6; ++i) {
913 TestIntSeq(TestIntSeq&&) noexcept = default;
914 TestIntSeq& operator=(TestIntSeq&&) noexcept = default;
915 TestIntSeq(const TestIntSeq&) = delete;
916 TestIntSeq& operator=(const TestIntSeq&) = delete;
921 TEST(Gen, NoGeneratorCopies) {
922 EXPECT_EQ(15, TestIntSeq() | sum);
923 auto x = TestIntSeq() | take(3);
924 EXPECT_EQ(6, std::move(x) | sum);
927 TEST(Gen, FromArray) {
928 int source[] = {2, 3, 5, 7};
929 auto gen = from(source);
930 EXPECT_EQ(2 * 3 * 5 * 7, gen | product);
933 TEST(Gen, FromStdArray) {
934 std::array<int,4> source {{2, 3, 5, 7}};
935 auto gen = from(source);
936 EXPECT_EQ(2 * 3 * 5 * 7, gen | product);
939 TEST(Gen, StringConcat) {
940 auto gen = seq(1, 10)
943 EXPECT_EQ("12345678910", gen | as<string>());
951 CopyCounter() : copies(0), moves(0) {
955 CopyCounter(CopyCounter&& source) noexcept {
956 *this = std::move(source);
960 CopyCounter(const CopyCounter& source) {
969 CopyCounter& operator=(const CopyCounter& source) {
970 this->copies = source.copies + 1;
971 this->moves = source.moves;
975 CopyCounter& operator=(CopyCounter&& source) {
976 this->copies = source.copies;
977 this->moves = source.moves + 1;
982 int CopyCounter::alive = 0;
984 TEST(Gen, CopyCount) {
985 vector<CopyCounter> originals;
986 originals.emplace_back();
987 EXPECT_EQ(1, originals.size());
988 EXPECT_EQ(0, originals.back().copies);
990 vector<CopyCounter> copies = from(originals) | as<vector>();
991 EXPECT_EQ(1, copies.back().copies);
992 EXPECT_EQ(0, copies.back().moves);
994 vector<CopyCounter> moves = from(originals) | move | as<vector>();
995 EXPECT_EQ(0, moves.back().copies);
996 EXPECT_EQ(1, moves.back().moves);
999 // test dynamics with various layers of nested arrays.
1000 TEST(Gen, Dynamic) {
1001 dynamic array1 = dynamic::array(1, 2);
1002 EXPECT_EQ(dynamic(3), from(array1) | sum);
1003 dynamic array2 = {{1}, {1, 2}};
1004 EXPECT_EQ(dynamic(4), from(array2) | rconcat | sum);
1005 dynamic array3 = {{{1}}, {{1}, {1, 2}}};
1006 EXPECT_EQ(dynamic(5), from(array3) | rconcat | rconcat | sum);
1009 TEST(Gen, DynamicObject) {
1010 const dynamic obj = dynamic::object(1, 2)(3, 4);
1011 EXPECT_EQ(dynamic(4), from(obj.keys()) | sum);
1012 EXPECT_EQ(dynamic(6), from(obj.values()) | sum);
1013 EXPECT_EQ(dynamic(4), from(obj.items()) | get<0>() | sum);
1014 EXPECT_EQ(dynamic(6), from(obj.items()) | get<1>() | sum);
1017 TEST(Gen, Collect) {
1018 auto s = from({7, 6, 5, 4, 3}) | as<set<int>>();
1019 EXPECT_EQ(s.size(), 5);
1025 auto s = from({1, 2});
1026 EXPECT_EQ((vector<int> { 1, 2, 1, 2, 1 }),
1027 s | cycle | take(5) | as<vector>());
1030 auto s = from({1, 2});
1031 EXPECT_EQ((vector<int> { 1, 2, 1, 2 }),
1032 s | cycle(2) | as<vector>());
1035 auto s = from({1, 2, 3});
1036 EXPECT_EQ((vector<int> { 1, 2, 1, 2, 1 }),
1037 s | take(2) | cycle | take(5) | as<vector>());
1040 auto s = empty<int>();
1041 EXPECT_EQ((vector<int> { }),
1042 s | cycle | take(4) | as<vector>());
1046 int* pcount = &count;
1047 auto countdown = GENERATOR(int) {
1048 ASSERT_GE(*pcount, 0)
1049 << "Cycle should have stopped when it didnt' get values!";
1050 for (int i = 1; i <= *pcount; ++i) {
1056 EXPECT_EQ((vector<int> { 1, 2, 3, 1, 2, 1}),
1057 s | cycle | take(7) | as<vector>());
1058 // take necessary as cycle returns an infinite generator
1062 TEST(Gen, Dereference) {
1064 const int x = 4, y = 2;
1065 auto s = from(std::initializer_list<const int*>({&x, nullptr, &y}));
1066 EXPECT_EQ(6, s | dereference | sum);
1069 vector<int> a { 1, 2 };
1070 vector<int> b { 3, 4 };
1071 vector<vector<int>*> pv { &a, nullptr, &b };
1074 | [&](vector<int>& v) {
1077 EXPECT_EQ(3, a.size());
1078 EXPECT_EQ(3, b.size());
1079 EXPECT_EQ(5, a.back());
1080 EXPECT_EQ(5, b.back());
1083 vector<std::map<int, int>> maps {
1100 | map([](std::map<int, int>& m) {
1101 return get_ptr(m, 3);
1107 vector<unique_ptr<int>> ups;
1108 ups.emplace_back(new int(3));
1110 ups.emplace_back(new int(7));
1111 EXPECT_EQ(10, from(ups) | dereference | sum);
1112 EXPECT_EQ(10, from(ups) | move | dereference | sum);
1116 TEST(Gen, Indirect) {
1118 EXPECT_EQ(&vs[0], from(vs) | indirect | first | unwrap);
1122 using std::runtime_error;
1123 EXPECT_THROW(from({"1", "a", "3"})
1128 from({"1", "a", "3"})
1129 | guard<runtime_error>([](runtime_error&, const char*) {
1130 return true; // continue
1135 from({"1", "a", "3"})
1136 | guard<runtime_error>([](runtime_error&, const char*) {
1137 return false; // break
1141 EXPECT_THROW(from({"1", "a", "3"})
1142 | guard<runtime_error>([](runtime_error&, const char* v) {
1154 EXPECT_EQ((vector<vector<int>> { {1} }),
1155 seq(1, 1) | batch(5) | as<vector>());
1156 EXPECT_EQ((vector<vector<int>> { {1, 2, 3}, {4, 5, 6}, {7, 8, 9}, {10, 11} }),
1157 seq(1, 11) | batch(3) | as<vector>());
1158 EXPECT_THROW(seq(1, 1) | batch(0) | as<vector>(),
1159 std::invalid_argument);
1162 TEST(Gen, BatchMove) {
1163 auto expected = vector<vector<int>>{ {0, 1}, {2, 3}, {4} };
1166 | mapped([](int i) { return std::unique_ptr<int>(new int(i)); })
1168 | mapped([](std::vector<std::unique_ptr<int>>& pVector) {
1169 std::vector<int> iVector;
1170 for (const auto& p : pVector) {
1171 iVector.push_back(*p);
1176 EXPECT_EQ(expected, actual);
1183 EXPECT_EQ(&x, j | indirect | first | unwrap);
1185 EXPECT_EQ(4, j | sum);
1191 EXPECT_EQ(&x, j | indirect | first | unwrap);
1193 EXPECT_EQ(5, j | sum);
1197 auto j = just(std::move(x));
1198 EXPECT_NE(&x, j | indirect | first | unwrap);
1200 EXPECT_EQ(3, j | sum);
1204 TEST(Gen, GroupBy) {
1205 vector<string> strs{"zero", "one", "two", "three", "four",
1206 "five", "six", "seven", "eight", "nine"};
1208 auto gb = from(strs) | groupBy([](const string& str) { return str.size(); });
1210 EXPECT_EQ(10, gb | mapOp(count) | sum);
1211 EXPECT_EQ(3, gb | count);
1213 vector<string> mode{"zero", "four", "five", "nine"};
1215 gb | maxBy([](const Group<size_t, string>& g) { return g.size(); })
1219 vector<string> largest{"three", "seven", "eight"};
1221 gb | maxBy([](const Group<size_t, string>& g) { return g.key(); })
1229 EXPECT_EQ(4, o | unwrap);
1230 EXPECT_THROW(e | unwrap, OptionalEmptyException);
1232 auto oup = folly::make_optional(folly::make_unique<int>(5));
1233 // optional has a value, and that value is non-null
1234 EXPECT_TRUE(oup | unwrap);
1235 EXPECT_EQ(5, *(oup | unwrap));
1236 EXPECT_TRUE(oup.hasValue()); // still has a pointer (null or not)
1237 EXPECT_TRUE(oup.value()); // that value isn't null
1239 auto moved1 = std::move(oup) | unwrapOr(folly::make_unique<int>(6));
1240 // oup still has a value, but now it's now nullptr since the pointer was moved
1242 EXPECT_TRUE(oup.hasValue());
1243 EXPECT_FALSE(oup.value());
1244 EXPECT_TRUE(moved1);
1245 EXPECT_EQ(5, *moved1);
1247 auto moved2 = std::move(oup) | unwrapOr(folly::make_unique<int>(7));
1248 // oup's still-valid nullptr value wins here, the pointer to 7 doesn't apply
1249 EXPECT_FALSE(moved2);
1252 auto moved3 = std::move(oup) | unwrapOr(folly::make_unique<int>(8));
1253 // oup is empty now, so the unwrapOr comes into play.
1254 EXPECT_TRUE(moved3);
1255 EXPECT_EQ(8, *moved3);
1258 // mixed types, with common type matching optional
1259 Optional<double> full(3.3);
1260 decltype(full) empty;
1261 auto fallback = unwrapOr(4);
1262 EXPECT_EQ(3.3, full | fallback);
1263 EXPECT_EQ(3.3, std::move(full) | fallback);
1264 EXPECT_EQ(3.3, full | std::move(fallback));
1265 EXPECT_EQ(3.3, std::move(full) | std::move(fallback));
1266 EXPECT_EQ(4.0, empty | fallback);
1267 EXPECT_EQ(4.0, std::move(empty) | fallback);
1268 EXPECT_EQ(4.0, empty | std::move(fallback));
1269 EXPECT_EQ(4.0, std::move(empty) | std::move(fallback));
1273 // mixed types, with common type matching fallback
1274 Optional<int> full(3);
1275 decltype(full) empty;
1276 auto fallback = unwrapOr(5.0); // type: double
1277 // if we chose 'int' as the common type, we'd see truncation here
1278 EXPECT_EQ(1.5, (full | fallback) / 2);
1279 EXPECT_EQ(1.5, (std::move(full) | fallback) / 2);
1280 EXPECT_EQ(1.5, (full | std::move(fallback)) / 2);
1281 EXPECT_EQ(1.5, (std::move(full) | std::move(fallback)) / 2);
1282 EXPECT_EQ(2.5, (empty | fallback) / 2);
1283 EXPECT_EQ(2.5, (std::move(empty) | fallback) / 2);
1284 EXPECT_EQ(2.5, (empty | std::move(fallback)) / 2);
1285 EXPECT_EQ(2.5, (std::move(empty) | std::move(fallback)) / 2);
1289 auto opt = folly::make_optional(std::make_shared<int>(8));
1290 auto fallback = unwrapOr(folly::make_unique<int>(9));
1291 // fallback must be std::move'd to be used
1292 EXPECT_EQ(8, *(opt | std::move(fallback)));
1293 EXPECT_TRUE(opt.value()); // shared_ptr copied out, not moved
1294 EXPECT_TRUE(opt); // value still present
1295 EXPECT_TRUE(fallback.value()); // fallback value not needed
1297 EXPECT_EQ(8, *(std::move(opt) | std::move(fallback)));
1298 EXPECT_FALSE(opt.value()); // shared_ptr moved out
1299 EXPECT_TRUE(opt); // gutted value still present
1300 EXPECT_TRUE(fallback.value()); // fallback value not needed
1304 EXPECT_FALSE(opt); // opt is empty now
1305 EXPECT_EQ(9, *(std::move(opt) | std::move(fallback)));
1306 EXPECT_FALSE(fallback.value()); // fallback moved out!
1310 // test with nullptr
1311 vector<int> v{1, 2};
1312 EXPECT_EQ(&v[1], from(v) | indirect | max | unwrap);
1314 EXPECT_FALSE(from(v) | indirect | max | unwrapOr(nullptr));
1318 // mixed type determined by fallback
1319 Optional<std::nullptr_t> empty;
1321 EXPECT_EQ(&x, empty | unwrapOr(&x));
1325 int main(int argc, char *argv[]) {
1326 testing::InitGoogleTest(&argc, argv);
1327 gflags::ParseCommandLineFlags(&argc, &argv, true);
1328 return RUN_ALL_TESTS();