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, 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);
357 EXPECT_THROW(stride(0), std::invalid_argument);
360 auto expected = vector<int>{1, 2, 3, 4};
365 EXPECT_EQ(expected, actual);
368 auto expected = vector<int>{1, 3, 5, 7};
373 EXPECT_EQ(expected, actual);
376 auto expected = vector<int>{1, 4, 7, 10};
381 EXPECT_EQ(expected, actual);
384 auto expected = vector<int>{1, 3, 5, 7, 9, 1, 4, 7, 10};
386 = ((seq(1, 10) | stride(2)) +
387 (seq(1, 10) | stride(3)))
389 EXPECT_EQ(expected, actual);
391 EXPECT_EQ(500, seq(1) | take(1000) | stride(2) | count);
392 EXPECT_EQ(10, seq(1) | take(1000) | stride(2) | take(10) | count);
396 std::mt19937 rnd(42);
401 std::unordered_map<int,int> hits;
402 const int kNumIters = 80;
403 for (int i = 0; i < kNumIters; i++) {
404 auto vec = sampler | as<vector<int>>();
405 EXPECT_EQ(vec.size(), 50);
406 auto uniq = fromConst(vec) | as<set<int>>();
407 EXPECT_EQ(uniq.size(), vec.size()); // sampling without replacement
413 // In 80 separate samples of our range, we should have seen every value
414 // at least once and no value all 80 times. (The odds of either of those
415 // events is 1/2^80).
416 EXPECT_EQ(hits.size(), 100);
417 for (auto hit: hits) {
418 EXPECT_GT(hit.second, 0);
419 EXPECT_LT(hit.second, kNumIters);
425 EXPECT_EQ((small | sum), 15);
426 EXPECT_EQ((small | take(3) | count), 3);
432 | mapped([](int x) { return x * x; })
435 EXPECT_EQ((vector<int>{25, 36, 49, 64}), gen | as<vector>());
440 auto expected = vector<int>{1, 4, 9, 16};
443 | mapped([](int x) { return x * x; })
444 | until([](int x) { return x > 20; })
446 EXPECT_EQ(expected, actual);
449 auto expected = vector<int>{ 0, 1, 4, 5, 8 };
451 = ((seq(0) | until([](int i) { return i > 1; })) +
452 (seq(4) | until([](int i) { return i > 5; })) +
453 (seq(8) | until([](int i) { return i > 9; })))
454 | until([](int i) { return i > 8; })
456 EXPECT_EQ(expected, actual);
460 auto expected = vector<int>{ 0, 1, 5, 6, 10 };
464 return seq(i * 5) | until([=](int j) { return j > i * 5 + 1; });
467 | until([](int i) { return i > 10; })
469 EXPECT_EQ(expected, actual);
474 TEST(Gen, Composed) {
475 // Operator, Operator
477 filter([](Optional<int>& o) { return o.hasValue(); })
478 | map([](Optional<int>& o) -> int& { return o.value(); });
479 std::vector<Optional<int>> opts {
480 none, 4, none, 6, none
482 EXPECT_EQ(4 * 4 + 6 * 6, from(opts) | valuesOf | map(square) | sum);
484 auto sumOpt = valuesOf | sum;
485 EXPECT_EQ(10, from(opts) | sumOpt);
489 std::vector<int> nums {2, 3, 5, 7};
490 std::map<int, int> mappings { { 3, 9}, {5, 25} };
491 auto gen = from(nums) + (from(mappings) | get<1>());
492 EXPECT_EQ(51, gen | sum);
493 EXPECT_EQ(5, gen | take(2) | sum);
494 EXPECT_EQ(26, gen | take(5) | sum);
498 std::vector<std::vector<int>> nums {{2, 3}, {5, 7}};
499 auto gen = from(nums) | rconcat;
500 EXPECT_EQ(17, gen | sum);
501 EXPECT_EQ(10, gen | take(3) | sum);
504 TEST(Gen, ConcatGen) {
505 auto gen = seq(1, 10)
506 | map([](int i) { return seq(1, i); })
508 EXPECT_EQ(220, gen | sum);
509 EXPECT_EQ(10, gen | take(6) | sum);
512 TEST(Gen, ConcatAlt) {
513 std::vector<std::vector<int>> nums {{2, 3}, {5, 7}};
514 auto actual = from(nums)
515 | map([](std::vector<int>& v) { return from(v); })
519 EXPECT_EQ(expected, actual);
523 auto expected = vector<int>{0, 3, 5, 6, 7, 8, 9};
525 from({8, 6, 7, 5, 3, 0, 9})
528 EXPECT_EQ(expected, actual);
531 TEST(Gen, OrderMoved) {
532 auto expected = vector<int>{0, 9, 25, 36, 49, 64, 81};
534 from({8, 6, 7, 5, 3, 0, 9})
539 EXPECT_EQ(expected, actual);
542 TEST(Gen, OrderTake) {
543 auto expected = vector<int>{9, 8, 7};
545 from({8, 6, 7, 5, 3, 0, 9})
546 | orderByDescending(square)
549 EXPECT_EQ(expected, actual);
552 TEST(Gen, Distinct) {
553 auto expected = vector<int>{3, 1, 2};
555 from({3, 1, 3, 2, 1, 2, 3})
558 EXPECT_EQ(expected, actual);
561 TEST(Gen, DistinctBy) { // 0 1 4 9 6 5 6 9 4 1 0
562 auto expected = vector<int>{0, 1, 2, 3, 4, 5};
565 | distinctBy([](int i) { return i * i % 10; })
567 EXPECT_EQ(expected, actual);
570 TEST(Gen, DistinctMove) { // 0 1 4 9 6 5 6 9 4 1 0
571 auto expected = vector<int>{0, 1, 2, 3, 4, 5};
574 | mapped([](int i) { return std::unique_ptr<int>(new int(i)); })
575 // see comment below about selector parameters for Distinct
576 | distinctBy([](const std::unique_ptr<int>& pi) { return *pi * *pi % 10; })
577 | mapped([](std::unique_ptr<int> pi) { return *pi; })
580 // NOTE(tjackson): the following line intentionally doesn't work:
581 // | distinctBy([](std::unique_ptr<int> pi) { return *pi * *pi % 10; })
582 // This is because distinctBy because the selector intentionally requires a
583 // const reference. If it required a move-reference, the value might get
584 // gutted by the selector before said value could be passed to downstream
586 EXPECT_EQ(expected, actual);
589 TEST(Gen, DistinctInfinite) {
590 // distinct should be able to handle an infinite sequence, provided that, of
591 // of cource, is it eventually made finite before returning the result.
592 auto expected = seq(0) | take(5) | as<vector>(); // 0 1 2 3 4
595 seq(0) // 0 1 2 3 4 5 6 7 ...
596 | mapped([](int i) { return i / 2; }) // 0 0 1 1 2 2 3 3 ...
597 | distinct // 0 1 2 3 4 5 6 7 ...
598 | take(5) // 0 1 2 3 4
601 EXPECT_EQ(expected, actual);
604 TEST(Gen, DistinctByInfinite) {
605 // Similarly to the DistinctInfinite test case, distinct by should be able to
606 // handle infinite sequences. Note that depending on how many values we take()
607 // at the end, the sequence may infinite loop. This is fine becasue we cannot
608 // solve the halting problem.
609 auto expected = vector<int>{1, 2};
611 seq(1) // 1 2 3 4 5 6 7 8 ...
612 | distinctBy([](int i) { return i % 2; }) // 1 2 (but might by infinite)
615 // Note that if we had take(3), this would infinite loop
617 EXPECT_EQ(expected, actual);
621 EXPECT_EQ(7, seq(1, 10)
622 | minBy([](int i) -> double {
630 auto gen = from({"three", "eleven", "four"});
632 EXPECT_EQ("eleven", gen | maxBy(&strlen) | unwrap);
636 auto odds = seq(2,10) | filter([](int i){ return i % 2; });
638 EXPECT_EQ(3, odds | min);
642 auto odds = seq(2,10) | filter([](int i){ return i % 2; });
644 EXPECT_EQ(9, odds | max);
648 string expected = "facebook";
649 string actual = "face";
650 from(StringPiece("book")) | appendTo(actual);
651 EXPECT_EQ(expected, actual);
654 TEST(Gen, FromRValue) {
656 // AFAICT The C++ Standard does not specify what happens to the rvalue
657 // reference of a std::vector when it is used as the 'other' for an rvalue
658 // constructor. Use fbvector because we're sure its size will be zero in
660 fbvector<int> v({1,2,3,4});
662 EXPECT_EQ(v.size(), 4); // ensure that the lvalue version was called!
663 auto expected = 1 * 2 * 3 * 4;
664 EXPECT_EQ(expected, q1 | product);
666 auto q2 = from(std::move(v));
667 EXPECT_EQ(v.size(), 0); // ensure that rvalue version was called
668 EXPECT_EQ(expected, q2 | product);
672 auto q = from([] {return vector<int>({3,7,5}); }());
673 EXPECT_EQ(expected, q | max);
676 for (auto size: {5, 1024, 16384, 1<<20}) {
677 auto q1 = from(vector<int>(size, 2));
678 auto q2 = from(vector<int>(size, 3));
679 // If the rvalue specialization is broken/gone, then the compiler will
680 // (disgustingly!) just store a *reference* to the temporary object,
681 // which is bad. Try to catch this by allocating two temporary vectors
682 // of the same size, so that they'll probably use the same underlying
683 // buffer if q1's vector is destructed before q2's vector is constructed.
684 EXPECT_EQ(size * 2 + size * 3, (q1 | sum) + (q2 | sum));
688 auto q = from(set<int>{1,2,3,2,1});
689 EXPECT_EQ(q | sum, 6);
694 auto expected = vector<int>{5, 6, 4, 7, 3, 8, 2, 9, 1, 10};
697 | orderBy([](int x) { return (5.1 - x) * (5.1 - x); })
699 EXPECT_EQ(expected, actual);
701 expected = seq(1, 10) | as<vector>();
704 | map([] (int x) { return 11 - x; })
707 EXPECT_EQ(expected, actual);
711 int expected = 2 * 3 * 4 * 5;
714 | foldl(1, multiply);
715 EXPECT_EQ(expected, actual);
719 int expected = 2 + 3 + 4 + 5;
720 auto actual = seq(2, 5) | reduce(add);
721 EXPECT_EQ(expected, actual | unwrap);
724 TEST(Gen, ReduceBad) {
725 auto gen = seq(1) | take(0);
726 auto actual = gen | reduce(add);
727 EXPECT_FALSE(actual); // Empty sequences are okay, they just yeild 'none'
731 std::vector<unique_ptr<int>> ptrs;
732 ptrs.emplace_back(new int(1));
733 EXPECT_NE(ptrs.front().get(), nullptr);
734 auto ptrs2 = from(ptrs) | move | as<vector>();
735 EXPECT_EQ(ptrs.front().get(), nullptr);
736 EXPECT_EQ(**ptrs2.data(), 1);
740 auto gen = seq(0) | filter([](int x) { return x > 3; });
741 EXPECT_EQ(4, gen | first | unwrap);
744 TEST(Gen, FromCopy) {
745 vector<int> v {3, 5};
747 auto copy = fromCopy(v);
748 EXPECT_EQ(8, src | sum);
749 EXPECT_EQ(8, copy | sum);
751 EXPECT_EQ(10, src | sum);
752 EXPECT_EQ(8, copy | sum);
756 std::map<int, int> pairs {
762 auto pairSrc = from(pairs);
763 auto keys = pairSrc | get<0>();
764 auto values = pairSrc | get<1>();
765 EXPECT_EQ(10, keys | sum);
766 EXPECT_EQ(30, values | sum);
767 EXPECT_EQ(30, keys | map(square) | sum);
769 EXPECT_EQ(15, keys | sum);
770 EXPECT_EQ(55, values | sum);
772 vector<tuple<int, int, int>> tuples {
775 make_tuple(3, 9, 27),
777 EXPECT_EQ(36, from(tuples) | get<2>() | sum);
780 TEST(Gen, notEmpty) {
781 EXPECT_TRUE(seq(0, 1) | notEmpty);
782 EXPECT_TRUE(just(1) | notEmpty);
783 EXPECT_FALSE(gen::range(0, 0) | notEmpty);
784 EXPECT_FALSE(from({1}) | take(0) | notEmpty);
788 EXPECT_FALSE(seq(0, 1) | isEmpty);
789 EXPECT_FALSE(just(1) | isEmpty);
790 EXPECT_TRUE(gen::range(0, 0) | isEmpty);
791 EXPECT_TRUE(from({1}) | take(0) | isEmpty);
795 EXPECT_TRUE(seq(0, 10) | any([](int i) { return i == 7; }));
796 EXPECT_FALSE(seq(0, 10) | any([](int i) { return i == 11; }));
800 EXPECT_TRUE(seq(0, 10) | all([](int i) { return i < 11; }));
801 EXPECT_FALSE(seq(0, 10) | all([](int i) { return i < 5; }));
802 EXPECT_FALSE(seq(0) | take(9999) | all([](int i) { return i < 10; }));
804 // empty lists satisfies all
805 EXPECT_TRUE(seq(0) | take(0) | all([](int i) { return i < 50; }));
806 EXPECT_TRUE(seq(0) | take(0) | all([](int i) { return i > 50; }));
809 TEST(Gen, Yielders) {
810 auto gen = GENERATOR(int) {
811 for (int i = 1; i <= 5; ++i) {
815 for (int i = 3; ; ++i) {
819 vector<int> expected {
820 1, 2, 3, 4, 5, 7, 9, 16, 25
822 EXPECT_EQ(expected, gen | take(9) | as<vector>());
825 TEST(Gen, NestedYield) {
826 auto nums = GENERATOR(int) {
827 for (int i = 1; ; ++i) {
831 auto gen = GENERATOR(int) {
832 nums | take(10) | yield;
833 seq(1, 5) | [&](int i) {
837 EXPECT_EQ(70, gen | sum);
840 TEST(Gen, MapYielders) {
843 return GENERATOR(int) {
845 for (i = 1; i < n; ++i)
852 vector<int> expected {
857 1, 2, 3, 4, 5, 4, 3, 2, 1,
859 EXPECT_EQ(expected, gen | as<vector>());
862 TEST(Gen, VirtualGen) {
863 VirtualGen<int> v(seq(1, 10));
864 EXPECT_EQ(55, v | sum);
866 EXPECT_EQ(385, v | sum);
868 EXPECT_EQ(55, v | sum);
869 EXPECT_EQ(30, v | take(4) | sum);
873 TEST(Gen, CustomType) {
877 auto gen = from({Foo{2}, Foo{3}})
878 | map([](const Foo& f) { return f.y; });
879 EXPECT_EQ(5, gen | sum);
882 TEST(Gen, NoNeedlessCopies) {
884 | map([](int x) { return unique_ptr<int>(new int(x)); })
885 | map([](unique_ptr<int> p) { return p; })
886 | map([](unique_ptr<int>&& p) { return std::move(p); })
887 | map([](const unique_ptr<int>& p) { return *p; });
888 EXPECT_EQ(15, gen | sum);
889 EXPECT_EQ(6, gen | take(3) | sum);
894 class TestIntSeq : public GenImpl<int, TestIntSeq> {
898 template <class Body>
899 bool apply(Body&& body) const {
900 for (int i = 1; i < 6; ++i) {
908 TestIntSeq(TestIntSeq&&) noexcept = default;
909 TestIntSeq& operator=(TestIntSeq&&) noexcept = default;
910 TestIntSeq(const TestIntSeq&) = delete;
911 TestIntSeq& operator=(const TestIntSeq&) = delete;
916 TEST(Gen, NoGeneratorCopies) {
917 EXPECT_EQ(15, TestIntSeq() | sum);
918 auto x = TestIntSeq() | take(3);
919 EXPECT_EQ(6, std::move(x) | sum);
922 TEST(Gen, FromArray) {
923 int source[] = {2, 3, 5, 7};
924 auto gen = from(source);
925 EXPECT_EQ(2 * 3 * 5 * 7, gen | product);
928 TEST(Gen, FromStdArray) {
929 std::array<int,4> source {{2, 3, 5, 7}};
930 auto gen = from(source);
931 EXPECT_EQ(2 * 3 * 5 * 7, gen | product);
934 TEST(Gen, StringConcat) {
935 auto gen = seq(1, 10)
938 EXPECT_EQ("12345678910", gen | as<string>());
946 CopyCounter() : copies(0), moves(0) {
950 CopyCounter(CopyCounter&& source) noexcept {
951 *this = std::move(source);
955 CopyCounter(const CopyCounter& source) {
964 CopyCounter& operator=(const CopyCounter& source) {
965 this->copies = source.copies + 1;
966 this->moves = source.moves;
970 CopyCounter& operator=(CopyCounter&& source) {
971 this->copies = source.copies;
972 this->moves = source.moves + 1;
977 int CopyCounter::alive = 0;
979 TEST(Gen, CopyCount) {
980 vector<CopyCounter> originals;
981 originals.emplace_back();
982 EXPECT_EQ(1, originals.size());
983 EXPECT_EQ(0, originals.back().copies);
985 vector<CopyCounter> copies = from(originals) | as<vector>();
986 EXPECT_EQ(1, copies.back().copies);
987 EXPECT_EQ(0, copies.back().moves);
989 vector<CopyCounter> moves = from(originals) | move | as<vector>();
990 EXPECT_EQ(0, moves.back().copies);
991 EXPECT_EQ(1, moves.back().moves);
994 // test dynamics with various layers of nested arrays.
996 dynamic array1 = {1, 2};
997 EXPECT_EQ(dynamic(3), from(array1) | sum);
998 dynamic array2 = {{1}, {1, 2}};
999 EXPECT_EQ(dynamic(4), from(array2) | rconcat | sum);
1000 dynamic array3 = {{{1}}, {{1}, {1, 2}}};
1001 EXPECT_EQ(dynamic(5), from(array3) | rconcat | rconcat | sum);
1004 TEST(Gen, DynamicObject) {
1005 const dynamic obj = dynamic::object(1, 2)(3, 4);
1006 EXPECT_EQ(dynamic(4), from(obj.keys()) | sum);
1007 EXPECT_EQ(dynamic(6), from(obj.values()) | sum);
1008 EXPECT_EQ(dynamic(4), from(obj.items()) | get<0>() | sum);
1009 EXPECT_EQ(dynamic(6), from(obj.items()) | get<1>() | sum);
1012 TEST(Gen, Collect) {
1013 auto s = from({7, 6, 5, 4, 3}) | as<set<int>>();
1014 EXPECT_EQ(s.size(), 5);
1020 auto s = from({1, 2});
1021 EXPECT_EQ((vector<int> { 1, 2, 1, 2, 1 }),
1022 s | cycle | take(5) | as<vector>());
1025 auto s = from({1, 2});
1026 EXPECT_EQ((vector<int> { 1, 2, 1, 2 }),
1027 s | cycle(2) | as<vector>());
1030 auto s = from({1, 2, 3});
1031 EXPECT_EQ((vector<int> { 1, 2, 1, 2, 1 }),
1032 s | take(2) | cycle | take(5) | as<vector>());
1035 auto s = empty<int>();
1036 EXPECT_EQ((vector<int> { }),
1037 s | cycle | take(4) | as<vector>());
1041 int* pcount = &count;
1042 auto countdown = GENERATOR(int) {
1043 ASSERT_GE(*pcount, 0)
1044 << "Cycle should have stopped when it didnt' get values!";
1045 for (int i = 1; i <= *pcount; ++i) {
1051 EXPECT_EQ((vector<int> { 1, 2, 3, 1, 2, 1}),
1052 s | cycle | take(7) | as<vector>());
1053 // take necessary as cycle returns an infinite generator
1057 TEST(Gen, Dereference) {
1059 const int x = 4, y = 2;
1060 auto s = from(std::initializer_list<const int*>({&x, nullptr, &y}));
1061 EXPECT_EQ(6, s | dereference | sum);
1064 vector<int> a { 1, 2 };
1065 vector<int> b { 3, 4 };
1066 vector<vector<int>*> pv { &a, nullptr, &b };
1069 | [&](vector<int>& v) {
1072 EXPECT_EQ(3, a.size());
1073 EXPECT_EQ(3, b.size());
1074 EXPECT_EQ(5, a.back());
1075 EXPECT_EQ(5, b.back());
1078 vector<std::map<int, int>> maps {
1095 | map([](std::map<int, int>& m) {
1096 return get_ptr(m, 3);
1102 vector<unique_ptr<int>> ups;
1103 ups.emplace_back(new int(3));
1105 ups.emplace_back(new int(7));
1106 EXPECT_EQ(10, from(ups) | dereference | sum);
1107 EXPECT_EQ(10, from(ups) | move | dereference | sum);
1111 TEST(Gen, Indirect) {
1113 EXPECT_EQ(&vs[0], from(vs) | indirect | first | unwrap);
1117 using std::runtime_error;
1118 EXPECT_THROW(from({"1", "a", "3"})
1123 from({"1", "a", "3"})
1124 | guard<runtime_error>([](runtime_error&, const char*) {
1125 return true; // continue
1130 from({"1", "a", "3"})
1131 | guard<runtime_error>([](runtime_error&, const char*) {
1132 return false; // break
1136 EXPECT_THROW(from({"1", "a", "3"})
1137 | guard<runtime_error>([](runtime_error&, const char* v) {
1149 EXPECT_EQ((vector<vector<int>> { {1} }),
1150 seq(1, 1) | batch(5) | as<vector>());
1151 EXPECT_EQ((vector<vector<int>> { {1, 2, 3}, {4, 5, 6}, {7, 8, 9}, {10, 11} }),
1152 seq(1, 11) | batch(3) | as<vector>());
1153 EXPECT_THROW(seq(1, 1) | batch(0) | as<vector>(),
1154 std::invalid_argument);
1157 TEST(Gen, BatchMove) {
1158 auto expected = vector<vector<int>>{ {0, 1}, {2, 3}, {4} };
1161 | mapped([](int i) { return std::unique_ptr<int>(new int(i)); })
1163 | mapped([](std::vector<std::unique_ptr<int>>& pVector) {
1164 std::vector<int> iVector;
1165 for (const auto& p : pVector) {
1166 iVector.push_back(*p);
1171 EXPECT_EQ(expected, actual);
1178 EXPECT_EQ(&x, j | indirect | first | unwrap);
1180 EXPECT_EQ(4, j | sum);
1186 EXPECT_EQ(&x, j | indirect | first | unwrap);
1188 EXPECT_EQ(5, j | sum);
1192 auto j = just(std::move(x));
1193 EXPECT_NE(&x, j | indirect | first | unwrap);
1195 EXPECT_EQ(3, j | sum);
1199 TEST(Gen, GroupBy) {
1200 vector<string> strs{"zero", "one", "two", "three", "four",
1201 "five", "six", "seven", "eight", "nine"};
1203 auto gb = from(strs) | groupBy([](const string& str) { return str.size(); });
1205 EXPECT_EQ(10, gb | mapOp(count) | sum);
1206 EXPECT_EQ(3, gb | count);
1208 vector<string> mode{"zero", "four", "five", "nine"};
1210 gb | maxBy([](const Group<size_t, string>& g) { return g.size(); })
1214 vector<string> largest{"three", "seven", "eight"};
1216 gb | maxBy([](const Group<size_t, string>& g) { return g.key(); })
1224 EXPECT_EQ(4, o | unwrap);
1225 EXPECT_THROW(e | unwrap, OptionalEmptyException);
1227 auto oup = folly::make_optional(folly::make_unique<int>(5));
1228 // optional has a value, and that value is non-null
1229 EXPECT_TRUE(oup | unwrap);
1230 EXPECT_EQ(5, *(oup | unwrap));
1231 EXPECT_TRUE(oup.hasValue()); // still has a pointer (null or not)
1232 EXPECT_TRUE(oup.value()); // that value isn't null
1234 auto moved1 = std::move(oup) | unwrapOr(folly::make_unique<int>(6));
1235 // oup still has a value, but now it's now nullptr since the pointer was moved
1237 EXPECT_TRUE(oup.hasValue());
1238 EXPECT_FALSE(oup.value());
1239 EXPECT_TRUE(moved1);
1240 EXPECT_EQ(5, *moved1);
1242 auto moved2 = std::move(oup) | unwrapOr(folly::make_unique<int>(7));
1243 // oup's still-valid nullptr value wins here, the pointer to 7 doesn't apply
1244 EXPECT_FALSE(moved2);
1247 auto moved3 = std::move(oup) | unwrapOr(folly::make_unique<int>(8));
1248 // oup is empty now, so the unwrapOr comes into play.
1249 EXPECT_TRUE(moved3);
1250 EXPECT_EQ(8, *moved3);
1253 // mixed types, with common type matching optional
1254 Optional<double> full(3.3);
1255 decltype(full) empty;
1256 auto fallback = unwrapOr(4);
1257 EXPECT_EQ(3.3, full | fallback);
1258 EXPECT_EQ(3.3, std::move(full) | fallback);
1259 EXPECT_EQ(3.3, full | std::move(fallback));
1260 EXPECT_EQ(3.3, std::move(full) | std::move(fallback));
1261 EXPECT_EQ(4.0, empty | fallback);
1262 EXPECT_EQ(4.0, std::move(empty) | fallback);
1263 EXPECT_EQ(4.0, empty | std::move(fallback));
1264 EXPECT_EQ(4.0, std::move(empty) | std::move(fallback));
1268 // mixed types, with common type matching fallback
1269 Optional<int> full(3);
1270 decltype(full) empty;
1271 auto fallback = unwrapOr(5.0); // type: double
1272 // if we chose 'int' as the common type, we'd see truncation here
1273 EXPECT_EQ(1.5, (full | fallback) / 2);
1274 EXPECT_EQ(1.5, (std::move(full) | fallback) / 2);
1275 EXPECT_EQ(1.5, (full | std::move(fallback)) / 2);
1276 EXPECT_EQ(1.5, (std::move(full) | std::move(fallback)) / 2);
1277 EXPECT_EQ(2.5, (empty | fallback) / 2);
1278 EXPECT_EQ(2.5, (std::move(empty) | fallback) / 2);
1279 EXPECT_EQ(2.5, (empty | std::move(fallback)) / 2);
1280 EXPECT_EQ(2.5, (std::move(empty) | std::move(fallback)) / 2);
1284 auto opt = folly::make_optional(std::make_shared<int>(8));
1285 auto fallback = unwrapOr(folly::make_unique<int>(9));
1286 // fallback must be std::move'd to be used
1287 EXPECT_EQ(8, *(opt | std::move(fallback)));
1288 EXPECT_TRUE(opt.value()); // shared_ptr copied out, not moved
1289 EXPECT_TRUE(opt); // value still present
1290 EXPECT_TRUE(fallback.value()); // fallback value not needed
1292 EXPECT_EQ(8, *(std::move(opt) | std::move(fallback)));
1293 EXPECT_FALSE(opt.value()); // shared_ptr moved out
1294 EXPECT_TRUE(opt); // gutted value still present
1295 EXPECT_TRUE(fallback.value()); // fallback value not needed
1299 EXPECT_FALSE(opt); // opt is empty now
1300 EXPECT_EQ(9, *(std::move(opt) | std::move(fallback)));
1301 EXPECT_FALSE(fallback.value()); // fallback moved out!
1305 // test with nullptr
1306 vector<int> v{1, 2};
1307 EXPECT_EQ(&v[1], from(v) | indirect | max | unwrap);
1309 EXPECT_FALSE(from(v) | indirect | max | unwrapOr(nullptr));
1313 // mixed type determined by fallback
1314 Optional<std::nullptr_t> empty;
1316 EXPECT_EQ(&x, empty | unwrapOr(&x));
1320 int main(int argc, char *argv[]) {
1321 testing::InitGoogleTest(&argc, argv);
1322 gflags::ParseCommandLineFlags(&argc, &argv, true);
1323 return RUN_ALL_TESTS();