ah-stl-zip_test.cc

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/*
                          Aleph_w
 
  Data structures & Algorithms
  version 2.0.0b
  https://github.com/lrleon/Aleph-w
 
  This file is part of Aleph-w library
 
  Copyright (c) 2002-2026 Leandro Rabindranath Leon
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
 
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
 
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/
 
 
#include <gtest/gtest.h>
#include <ah-stl-zip.H>
 
#include <vector>
#include <list>
#include <set>
#include <deque>
#include <array>
#include <string>
#include <numeric>
 
using namespace Aleph;
 
//==============================================================================
// Basic StlZipView Tests
//==============================================================================
 
class StlZipViewTest : public ::testing::Test
{
protected:
  std::vector<int> vi = {1, 2, 3, 4, 5};
  std::vector<std::string> vs = {"a", "b", "c", "d", "e"};
  std::list<double> ld = {1.1, 2.2, 3.3, 4.4, 5.5};
};
 
TEST_F(StlZipViewTest, BasicIteration)
{
  int count = 0;
  for (auto [i, s] : stl_zip(vi, vs))
    {
      EXPECT_EQ(i, vi[count]);
      EXPECT_EQ(s, vs[count]);
      ++count;
    }
  EXPECT_EQ(count, 5);
}
 
TEST_F(StlZipViewTest, ThreeContainers)
{
  int count = 0;
  for (auto [i, s, d] : stl_zip(vi, vs, ld))
    {
      EXPECT_EQ(i, vi[count]);
      EXPECT_EQ(s, vs[count]);
      ++count;
    }
  EXPECT_EQ(count, 5);
}
 
TEST_F(StlZipViewTest, DifferentLengths_StopsAtShortest)
{
  std::vector<int> short_vec = {10, 20};
  
  int count = 0;
  for (auto [i, s] : stl_zip(short_vec, vs))
    {
      (void)i;
      (void)s;
      ++count;
    }
  EXPECT_EQ(count, 2);  // Stops at shorter container
}
 
TEST_F(StlZipViewTest, EmptyContainer)
{
  std::vector<int> empty_vec;
  
  int count = 0;
  for (auto [i, s] : stl_zip(empty_vec, vs))
    {
      (void)i;
      (void)s;
      ++count;
    }
  EXPECT_EQ(count, 0);
}
 
TEST_F(StlZipViewTest, SingleElement)
{
  std::vector<int> single = {42};
  std::vector<std::string> single_s = {"answer"};
  
  int count = 0;
  for (auto [i, s] : stl_zip(single, single_s))
    {
      EXPECT_EQ(i, 42);
      EXPECT_EQ(s, "answer");
      ++count;
    }
  EXPECT_EQ(count, 1);
}
 
TEST_F(StlZipViewTest, ViewSize)
{
  auto view = stl_zip(vi, vs);
  EXPECT_EQ(view.size(), 5);
}
 
TEST_F(StlZipViewTest, ViewEmpty)
{
  std::vector<int> empty_vec;
  auto view = stl_zip(empty_vec, vs);
  EXPECT_TRUE(view.empty());
  
  auto view2 = stl_zip(vi, vs);
  EXPECT_FALSE(view2.empty());
}
 
//==============================================================================
// Different Container Types
//==============================================================================
 
TEST(StlZipContainerTypes, VectorAndList)
{
  std::vector<int> v = {1, 2, 3};
  std::list<int> l = {10, 20, 30};
  
  std::vector<int> sums;
  for (auto [a, b] : stl_zip(v, l))
    sums.push_back(a + b);
  
  EXPECT_EQ(sums.size(), 3);
  EXPECT_EQ(sums[0], 11);
  EXPECT_EQ(sums[1], 22);
  EXPECT_EQ(sums[2], 33);
}
 
TEST(StlZipContainerTypes, VectorAndSet)
{
  std::vector<int> v = {1, 2, 3};
  std::set<int> s = {100, 200, 300};
  
  int count = 0;
  for (auto [a, b] : stl_zip(v, s))
    {
      EXPECT_EQ(a, count + 1);
      ++count;
    }
  EXPECT_EQ(count, 3);
}
 
TEST(StlZipContainerTypes, VectorAndDeque)
{
  std::vector<int> v = {1, 2, 3};
  std::deque<std::string> d = {"x", "y", "z"};
  
  int count = 0;
  for (auto [num, str] : stl_zip(v, d))
    {
      (void)num;
      (void)str;
      ++count;
    }
  EXPECT_EQ(count, 3);
}
 
TEST(StlZipContainerTypes, StdArray)
{
  std::array<int, 3> a1 = {1, 2, 3};
  std::array<int, 3> a2 = {10, 20, 30};
  
  std::vector<int> products;
  for (auto [x, y] : stl_zip(a1, a2))
    products.push_back(x * y);
  
  EXPECT_EQ(products.size(), 3);
  EXPECT_EQ(products[0], 10);
  EXPECT_EQ(products[1], 40);
  EXPECT_EQ(products[2], 90);
}
 
TEST(StlZipContainerTypes, ManyContainers)
{
  std::vector<int> v1 = {1, 2};
  std::vector<int> v2 = {10, 20};
  std::vector<int> v3 = {100, 200};
  std::vector<int> v4 = {1000, 2000};
  
  int count = 0;
  for (auto [a, b, c, d] : stl_zip(v1, v2, v3, v4))
    {
      if (count == 0)
        {
          EXPECT_EQ(a, 1);
          EXPECT_EQ(b, 10);
          EXPECT_EQ(c, 100);
          EXPECT_EQ(d, 1000);
        }
      ++count;
    }
  EXPECT_EQ(count, 2);
}
 
//==============================================================================
// Functional Operations: stl_zip_all
//==============================================================================
 
TEST(StlZipAll, AllTrue)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  bool result = stl_zip_all([](auto t) {
    return std::get<0>(t) < std::get<1>(t);
  }, xs, ys);
  
  EXPECT_TRUE(result);
}
 
TEST(StlZipAll, SomeFalse)
{
  std::vector<int> xs = {1, 200, 3};
  std::vector<int> ys = {10, 20, 30};
  
  bool result = stl_zip_all([](auto t) {
    return std::get<0>(t) < std::get<1>(t);
  }, xs, ys);
  
  EXPECT_FALSE(result);
}
 
TEST(StlZipAll, EmptyContainers)
{
  std::vector<int> empty1, empty2;
  
  bool result = stl_zip_all([](auto) { return false; }, empty1, empty2);
  
  EXPECT_TRUE(result);  // Vacuously true
}
 
TEST(StlZipAll, EqualLengthCheck)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  bool result = stl_zip_all_eq([](auto t) {
    return std::get<0>(t) < std::get<1>(t);
  }, xs, ys);
  
  EXPECT_TRUE(result);
  
  // Different lengths
  std::vector<int> short_vec = {1, 2};
  result = stl_zip_all_eq([](auto) { return true; }, short_vec, ys);
  EXPECT_FALSE(result);  // Lengths differ
}
 
//==============================================================================
// Functional Operations: stl_zip_exists / stl_zip_any
//==============================================================================
 
TEST(StlZipExists, Found)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  bool result = stl_zip_exists([](auto t) {
    return std::get<0>(t) == 2;
  }, xs, ys);
  
  EXPECT_TRUE(result);
}
 
TEST(StlZipExists, NotFound)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  bool result = stl_zip_exists([](auto t) {
    return std::get<0>(t) == 99;
  }, xs, ys);
  
  EXPECT_FALSE(result);
}
 
TEST(StlZipExists, EmptyContainers)
{
  std::vector<int> empty1, empty2;
  
  bool result = stl_zip_exists([](auto) { return true; }, empty1, empty2);
  
  EXPECT_FALSE(result);
}
 
TEST(StlZipAny, AliasWorks)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  bool result = stl_zip_any([](auto t) {
    return std::get<0>(t) > 2;
  }, xs, ys);
  
  EXPECT_TRUE(result);
}
 
TEST(StlZipNone, AllFalse)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  bool result = stl_zip_none([](auto t) {
    return std::get<0>(t) > 100;
  }, xs, ys);
  
  EXPECT_TRUE(result);
}
 
//==============================================================================
// Functional Operations: stl_zip_for_each
//==============================================================================
 
TEST(StlZipForEach, BasicForEach)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  std::vector<int> sums;
  stl_zip_for_each([&sums](auto t) {
    sums.push_back(std::get<0>(t) + std::get<1>(t));
  }, xs, ys);
  
  EXPECT_EQ(sums.size(), 3);
  EXPECT_EQ(sums[0], 11);
  EXPECT_EQ(sums[1], 22);
  EXPECT_EQ(sums[2], 33);
}
 
TEST(StlZipForEach, WithIndex)
{
  std::vector<int> xs = {10, 20, 30};
  std::vector<std::string> ys = {"a", "b", "c"};
  
  std::vector<size_t> indices;
  stl_zip_for_each_indexed([&indices](size_t idx, auto) {
    indices.push_back(idx);
  }, xs, ys);
  
  EXPECT_EQ(indices.size(), 3);
  EXPECT_EQ(indices[0], 0);
  EXPECT_EQ(indices[1], 1);
  EXPECT_EQ(indices[2], 2);
}
 
//==============================================================================
// Functional Operations: stl_zip_foldl / stl_zip_reduce
//==============================================================================
 
TEST(StlZipFoldl, SumProducts)
{
  std::vector<int> prices = {10, 20, 30};
  std::vector<int> quantities = {2, 3, 1};
  
  int total = stl_zip_foldl(0, [](int acc, auto t) {
    return acc + std::get<0>(t) * std::get<1>(t);
  }, prices, quantities);
  
  // 10*2 + 20*3 + 30*1 = 20 + 60 + 30 = 110
  EXPECT_EQ(total, 110);
}
 
TEST(StlZipFoldl, ConcatStrings)
{
  std::vector<int> nums = {1, 2, 3};
  std::vector<std::string> strs = {"a", "b", "c"};
  
  std::string result = stl_zip_foldl(std::string(""), [](std::string acc, auto t) {
    return acc + std::to_string(std::get<0>(t)) + std::get<1>(t);
  }, nums, strs);
  
  EXPECT_EQ(result, "1a2b3c");
}
 
TEST(StlZipReduce, AliasWorks)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  int sum = stl_zip_reduce(0, [](int acc, auto t) {
    return acc + std::get<0>(t) + std::get<1>(t);
  }, xs, ys);
  
  EXPECT_EQ(sum, 66);  // 1+10 + 2+20 + 3+30 = 66
}
 
//==============================================================================
// Functional Operations: stl_zip_map
//==============================================================================
 
TEST(StlZipMap, BasicMap)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  auto sums = stl_zip_map([](auto t) {
    return std::get<0>(t) + std::get<1>(t);
  }, xs, ys);
  
  EXPECT_EQ(sums.size(), 3);
  EXPECT_EQ(sums[0], 11);
  EXPECT_EQ(sums[1], 22);
  EXPECT_EQ(sums[2], 33);
}
 
TEST(StlZipMap, DifferentReturnType)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  auto strs = stl_zip_map([](auto t) {
    return std::to_string(std::get<0>(t)) + "+" + std::to_string(std::get<1>(t));
  }, xs, ys);
  
  EXPECT_EQ(strs.size(), 3);
  EXPECT_EQ(strs[0], "1+10");
  EXPECT_EQ(strs[1], "2+20");
  EXPECT_EQ(strs[2], "3+30");
}
 
//==============================================================================
// Functional Operations: stl_zip_filter
//==============================================================================
 
TEST(StlZipFilter, BasicFilter)
{
  std::vector<int> xs = {1, 2, 3, 4, 5};
  std::vector<int> ys = {10, 20, 30, 40, 50};
  
  auto result = stl_zip_filter([](auto t) {
    return std::get<0>(t) % 2 == 0;  // Even xs
  }, xs, ys);
  
  EXPECT_EQ(result.size(), 2);  // (2,20) and (4,40)
}
 
TEST(StlZipFilter, NoMatches)
{
  std::vector<int> xs = {1, 3, 5};
  std::vector<int> ys = {10, 30, 50};
  
  auto result = stl_zip_filter([](auto t) {
    return std::get<0>(t) % 2 == 0;  // No even numbers
  }, xs, ys);
  
  EXPECT_EQ(result.size(), 0);
}
 
//==============================================================================
// Functional Operations: stl_zip_find_first
//==============================================================================
 
TEST(StlZipFindFirst, Found)
{
  std::vector<int> xs = {1, 2, 3, 4, 5};
  std::vector<std::string> ys = {"a", "b", "c", "d", "e"};
  
  auto result = stl_zip_find_first([](auto t) {
    return std::get<0>(t) == 3;
  }, xs, ys);
  
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(std::get<0>(*result), 3);
  EXPECT_EQ(std::get<1>(*result), "c");
}
 
TEST(StlZipFindFirst, NotFound)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  auto result = stl_zip_find_first([](auto t) {
    return std::get<0>(t) == 99;
  }, xs, ys);
  
  EXPECT_FALSE(result.has_value());
}
 
//==============================================================================
// Functional Operations: stl_zip_count
//==============================================================================
 
TEST(StlZipCount, CountMatches)
{
  std::vector<int> xs = {1, 2, 3, 4, 5};
  std::vector<int> ys = {10, 20, 30, 40, 50};
  
  size_t count = stl_zip_count([](auto t) {
    return std::get<0>(t) % 2 == 0;
  }, xs, ys);
  
  EXPECT_EQ(count, 2);  // 2 and 4
}
 
TEST(StlZipLength, BasicLength)
{
  std::vector<int> xs = {1, 2, 3, 4, 5};
  std::vector<int> ys = {10, 20, 30, 40, 50};
  
  EXPECT_EQ(stl_zip_length(xs, ys), 5);
  
  std::vector<int> short_vec = {1, 2};
  EXPECT_EQ(stl_zip_length(short_vec, ys), 2);
}
 
TEST(StlZipEqualLength, EqualLengths)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  EXPECT_TRUE(stl_zip_equal_length(xs, ys));
}
 
TEST(StlZipEqualLength, DifferentLengths)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20};
  
  EXPECT_FALSE(stl_zip_equal_length(xs, ys));
}
 
//==============================================================================
// Functional Operations: stl_zip_nth
//==============================================================================
 
TEST(StlZipNth, ValidIndex)
{
  std::vector<int> xs = {1, 2, 3, 4, 5};
  std::vector<std::string> ys = {"a", "b", "c", "d", "e"};
  
  auto result = stl_zip_nth(2, xs, ys);
  
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(std::get<0>(*result), 3);
  EXPECT_EQ(std::get<1>(*result), "c");
}
 
TEST(StlZipNth, InvalidIndex)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  auto result = stl_zip_nth(10, xs, ys);
  
  EXPECT_FALSE(result.has_value());
}
 
//==============================================================================
// Functional Operations: stl_zip_take / stl_zip_drop
//==============================================================================
 
TEST(StlZipTake, TakeFirst)
{
  std::vector<int> xs = {1, 2, 3, 4, 5};
  std::vector<int> ys = {10, 20, 30, 40, 50};
  
  auto result = stl_zip_take(3, xs, ys);
  
  EXPECT_EQ(result.size(), 3);
  EXPECT_EQ(std::get<0>(result[0]), 1);
  EXPECT_EQ(std::get<0>(result[2]), 3);
}
 
TEST(StlZipTake, TakeMoreThanAvailable)
{
  std::vector<int> xs = {1, 2};
  std::vector<int> ys = {10, 20};
  
  auto result = stl_zip_take(10, xs, ys);
  
  EXPECT_EQ(result.size(), 2);
}
 
TEST(StlZipDrop, DropFirst)
{
  std::vector<int> xs = {1, 2, 3, 4, 5};
  std::vector<int> ys = {10, 20, 30, 40, 50};
  
  auto result = stl_zip_drop(2, xs, ys);
  
  EXPECT_EQ(result.size(), 3);
  EXPECT_EQ(std::get<0>(result[0]), 3);
  EXPECT_EQ(std::get<0>(result[2]), 5);
}
 
TEST(StlZipDrop, DropAll)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  auto result = stl_zip_drop(10, xs, ys);
  
  EXPECT_EQ(result.size(), 0);
}
 
//==============================================================================
// Functional Operations: stl_zip_partition
//==============================================================================
 
TEST(StlZipPartition, BasicPartition)
{
  std::vector<int> xs = {1, 2, 3, 4, 5};
  std::vector<std::string> ys = {"a", "b", "c", "d", "e"};
  
  auto [evens, odds] = stl_zip_partition([](auto t) {
    return std::get<0>(t) % 2 == 0;
  }, xs, ys);
  
  EXPECT_EQ(evens.size(), 2);  // (2,"b"), (4,"d")
  EXPECT_EQ(odds.size(), 3);   // (1,"a"), (3,"c"), (5,"e")
}
 
//==============================================================================
// Functional Operations: stl_zip_to_vector
//==============================================================================
 
TEST(StlZipToVector, Materialize)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<std::string> ys = {"a", "b", "c"};
  
  auto result = stl_zip_to_vector(xs, ys);
  
  EXPECT_EQ(result.size(), 3);
  EXPECT_EQ(std::get<0>(result[0]), 1);
  EXPECT_EQ(std::get<1>(result[0]), "a");
}
 
//==============================================================================
// Traverse Operations
//==============================================================================
 
TEST(StlZipTraverse, AllTrue)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  bool result = stl_zip_traverse([](auto t) {
    return std::get<0>(t) < std::get<1>(t);
  }, xs, ys);
  
  EXPECT_TRUE(result);
}
 
TEST(StlZipTraverse, StopsEarly)
{
  std::vector<int> xs = {1, 200, 3};
  std::vector<int> ys = {10, 20, 30};
  
  int count = 0;
  bool result = stl_zip_traverse([&count](auto t) {
    ++count;
    return std::get<0>(t) < std::get<1>(t);
  }, xs, ys);
  
  EXPECT_FALSE(result);
  EXPECT_EQ(count, 2);  // Stopped at second element
}
 
//==============================================================================
// Comparison: stl_zip_cmp
//==============================================================================
 
TEST(StlZipCmp, AllEqual)
{
  std::vector<int> a = {1, 2, 3};
  std::vector<int> b = {1, 2, 3};
  std::vector<int> c = {1, 2, 3};
  
  bool result = stl_zip_cmp([](auto x, auto y) { return x == y; }, a, b, c);
  
  EXPECT_TRUE(result);
}
 
TEST(StlZipCmp, NotAllEqual)
{
  std::vector<int> a = {1, 2, 3};
  std::vector<int> b = {1, 99, 3};
  std::vector<int> c = {1, 2, 3};
  
  bool result = stl_zip_cmp([](auto x, auto y) { return x == y; }, a, b, c);
  
  EXPECT_FALSE(result);
}
 
//==============================================================================
// Edge Cases
//==============================================================================
 
TEST(StlZipEdgeCases, BothEmpty)
{
  std::vector<int> empty1, empty2;
  
  auto view = stl_zip(empty1, empty2);
  EXPECT_TRUE(view.empty());
  EXPECT_EQ(view.size(), 0);
}
 
TEST(StlZipEdgeCases, OneEmpty)
{
  std::vector<int> empty;
  std::vector<int> nonempty = {1, 2, 3};
  
  auto view = stl_zip(empty, nonempty);
  EXPECT_TRUE(view.empty());
}
 
TEST(StlZipEdgeCases, VeryLongContainers)
{
  std::vector<int> xs(1000);
  std::vector<int> ys(1000);
  std::iota(xs.begin(), xs.end(), 0);
  std::iota(ys.begin(), ys.end(), 1000);
  
  int sum = stl_zip_foldl(0, [](int acc, auto t) {
    return acc + std::get<0>(t) + std::get<1>(t);
  }, xs, ys);
  
  // Sum of 0..999 + sum of 1000..1999
  // = 999*1000/2 + (1999*2000/2 - 999*1000/2)
  // = 499500 + 1499500 = 1999000
  EXPECT_EQ(sum, 1999000);
}
 
//==============================================================================
// Enumerate Tests
//==============================================================================
 
TEST(StlEnumerate, Basic)
{
  std::vector<std::string> names = {"Alice", "Bob", "Charlie"};
  
  std::vector<size_t> indices;
  std::vector<std::string> collected_names;
  
  for (auto [idx, name] : stl_enumerate(names))
    {
      indices.push_back(idx);
      collected_names.push_back(name);
    }
  
  EXPECT_EQ(indices.size(), 3);
  EXPECT_EQ(indices[0], 0);
  EXPECT_EQ(indices[1], 1);
  EXPECT_EQ(indices[2], 2);
  EXPECT_EQ(collected_names[0], "Alice");
}
 
TEST(StlEnumerate, Empty)
{
  std::vector<int> empty;
  
  int count = 0;
  for (auto [idx, val] : stl_enumerate(empty))
    {
      (void)idx;
      (void)val;
      ++count;
    }
  
  EXPECT_EQ(count, 0);
}
 
//==============================================================================
// Take While / Drop While Tests
//==============================================================================
 
TEST(StlZipTakeWhile, Basic)
{
  std::vector<int> xs = {1, 2, 3, 10, 4, 5};
  std::vector<int> ys = {10, 20, 30, 100, 40, 50};
  
  auto result = stl_zip_take_while([](auto t) {
    return std::get<0>(t) < 10;
  }, xs, ys);
  
  EXPECT_EQ(result.size(), 3);
  EXPECT_EQ(std::get<0>(result[0]), 1);
  EXPECT_EQ(std::get<0>(result[2]), 3);
}
 
TEST(StlZipTakeWhile, TakeNone)
{
  std::vector<int> xs = {10, 20, 30};
  std::vector<int> ys = {1, 2, 3};
  
  auto result = stl_zip_take_while([](auto t) {
    return std::get<0>(t) < 5;
  }, xs, ys);
  
  EXPECT_EQ(result.size(), 0);
}
 
TEST(StlZipDropWhile, Basic)
{
  std::vector<int> xs = {1, 2, 3, 10, 4, 5};
  std::vector<int> ys = {10, 20, 30, 100, 40, 50};
  
  auto result = stl_zip_drop_while([](auto t) {
    return std::get<0>(t) < 10;
  }, xs, ys);
  
  EXPECT_EQ(result.size(), 3);
  EXPECT_EQ(std::get<0>(result[0]), 10);
}
 
TEST(StlZipDropWhile, DropAll)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  auto result = stl_zip_drop_while([](auto t) {
    return std::get<0>(t) < 100;
  }, xs, ys);
  
  EXPECT_EQ(result.size(), 0);
}
 
//==============================================================================
// First / Last Tests
//==============================================================================
 
TEST(StlZipFirst, Basic)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<std::string> ys = {"a", "b", "c"};
  
  auto result = stl_zip_first(xs, ys);
  
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(std::get<0>(*result), 1);
  EXPECT_EQ(std::get<1>(*result), "a");
}
 
TEST(StlZipFirst, Empty)
{
  std::vector<int> empty1, empty2;
  
  auto result = stl_zip_first(empty1, empty2);
  
  EXPECT_FALSE(result.has_value());
}
 
TEST(StlZipLast, Basic)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<std::string> ys = {"a", "b", "c"};
  
  auto result = stl_zip_last(xs, ys);
  
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(std::get<0>(*result), 3);
  EXPECT_EQ(std::get<1>(*result), "c");
}
 
TEST(StlZipFindLast, Basic)
{
  std::vector<int> xs = {1, 2, 3, 4, 5};
  std::vector<int> ys = {10, 20, 30, 40, 50};
  
  auto result = stl_zip_find_last([](auto t) {
    return std::get<0>(t) % 2 == 0;
  }, xs, ys);
  
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(std::get<0>(*result), 4);  // Last even
}
 
TEST(StlZipFindIndex, Found)
{
  std::vector<int> xs = {1, 2, 3, 4, 5};
  std::vector<int> ys = {10, 20, 30, 40, 50};
  
  size_t idx = stl_zip_find_index([](auto t) {
    return std::get<0>(t) == 3;
  }, xs, ys);
  
  EXPECT_EQ(idx, 2);
}
 
TEST(StlZipFindIndex, NotFound)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  size_t idx = stl_zip_find_index([](auto t) {
    return std::get<0>(t) == 99;
  }, xs, ys);
  
  EXPECT_EQ(idx, 3);  // Returns total count when not found
}
 
//==============================================================================
// Unzip Tests
//==============================================================================
 
TEST(StlUnzip, Pairs)
{
  std::vector<std::pair<int, std::string>> pairs = {{1, "a"}, {2, "b"}, {3, "c"}};
  
  auto [nums, strs] = stl_unzip(pairs);
  
  EXPECT_EQ(nums.size(), 3);
  EXPECT_EQ(strs.size(), 3);
  EXPECT_EQ(nums[0], 1);
  EXPECT_EQ(strs[2], "c");
}
 
TEST(StlUnzipTuple, Basic)
{
  std::vector<std::tuple<int, double, char>> tuples = {
    {1, 1.1, 'a'}, {2, 2.2, 'b'}, {3, 3.3, 'c'}
  };
  
  auto [ints, doubles, chars] = stl_unzip_tuple(tuples);
  
  EXPECT_EQ(ints.size(), 3);
  EXPECT_EQ(doubles.size(), 3);
  EXPECT_EQ(chars.size(), 3);
  EXPECT_EQ(ints[1], 2);
  EXPECT_DOUBLE_EQ(doubles[1], 2.2);
  EXPECT_EQ(chars[1], 'b');
}
 
//==============================================================================
// Adjacent Tests
//==============================================================================
 
TEST(StlAdjacent, Basic)
{
  std::vector<int> v = {1, 2, 3, 4, 5};
  
  auto pairs = stl_adjacent(v);
  
  EXPECT_EQ(pairs.size(), 4);
  EXPECT_EQ(pairs[0].first, 1);
  EXPECT_EQ(pairs[0].second, 2);
  EXPECT_EQ(pairs[3].first, 4);
  EXPECT_EQ(pairs[3].second, 5);
}
 
TEST(StlAdjacent, SingleElement)
{
  std::vector<int> v = {42};
  
  auto pairs = stl_adjacent(v);
  
  EXPECT_EQ(pairs.size(), 0);
}
 
TEST(StlAdjacent, Empty)
{
  std::vector<int> v;
  
  auto pairs = stl_adjacent(v);
  
  EXPECT_EQ(pairs.size(), 0);
}
 
TEST(StlAdjacentMap, Differences)
{
  std::vector<int> v = {1, 3, 6, 10};
  
  auto diffs = stl_adjacent_map([](int a, int b) { return b - a; }, v);
  
  EXPECT_EQ(diffs.size(), 3);
  EXPECT_EQ(diffs[0], 2);
  EXPECT_EQ(diffs[1], 3);
  EXPECT_EQ(diffs[2], 4);
}
 
TEST(StlAdjacentAll, Sorted)
{
  std::vector<int> sorted = {1, 2, 3, 4, 5};
  std::vector<int> unsorted = {1, 3, 2, 4, 5};
  
  EXPECT_TRUE(stl_adjacent_all([](int a, int b) { return a < b; }, sorted));
  EXPECT_FALSE(stl_adjacent_all([](int a, int b) { return a < b; }, unsorted));
}
 
TEST(StlAdjacentExists, HasDuplicate)
{
  std::vector<int> with_dup = {1, 2, 2, 3};
  std::vector<int> no_dup = {1, 2, 3, 4};
  
  EXPECT_TRUE(stl_adjacent_exists([](int a, int b) { return a == b; }, with_dup));
  EXPECT_FALSE(stl_adjacent_exists([](int a, int b) { return a == b; }, no_dup));
}
 
//==============================================================================
// ML-style Operations Tests
//==============================================================================
 
TEST(StlZipMapi, Basic)
{
  std::vector<int> xs = {10, 20, 30};
  std::vector<int> ys = {1, 2, 3};
  
  auto results = stl_zip_mapi([](size_t i, auto t) {
    return std::to_string(i) + ":" + std::to_string(std::get<0>(t) + std::get<1>(t));
  }, xs, ys);
  
  EXPECT_EQ(results.size(), 3);
  EXPECT_EQ(results[0], "0:11");
  EXPECT_EQ(results[1], "1:22");
  EXPECT_EQ(results[2], "2:33");
}
 
TEST(StlZipFilteri, EvenIndices)
{
  std::vector<int> xs = {10, 20, 30, 40, 50};
  std::vector<std::string> ys = {"a", "b", "c", "d", "e"};
  
  auto evens = stl_zip_filteri([](size_t i, auto) {
    return i % 2 == 0;
  }, xs, ys);
  
  EXPECT_EQ(evens.size(), 3);
  EXPECT_EQ(std::get<0>(evens[0]), 10);
  EXPECT_EQ(std::get<0>(evens[1]), 30);
  EXPECT_EQ(std::get<0>(evens[2]), 50);
}
 
TEST(StlZipScanLeft, RunningSum)
{
  std::vector<int> xs = {1, 2, 3, 4};
  std::vector<int> ys = {10, 20, 30, 40};
  
  auto sums = stl_zip_scan_left(0, [](int acc, auto t) {
    return acc + std::get<0>(t);
  }, xs, ys);
  
  EXPECT_EQ(sums.size(), 5);
  EXPECT_EQ(sums[0], 0);   // init
  EXPECT_EQ(sums[1], 1);   // 0 + 1
  EXPECT_EQ(sums[2], 3);   // 1 + 2
  EXPECT_EQ(sums[3], 6);   // 3 + 3
  EXPECT_EQ(sums[4], 10);  // 6 + 4
}
 
TEST(StlZipScanLeft, RunningProduct)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  auto products = stl_zip_scan_left(1, [](int acc, auto t) {
    return acc * std::get<0>(t) * std::get<1>(t);
  }, xs, ys);
  
  EXPECT_EQ(products.size(), 4);
  EXPECT_EQ(products[0], 1);      // init
  EXPECT_EQ(products[1], 10);     // 1 * 1 * 10
  EXPECT_EQ(products[2], 400);    // 10 * 2 * 20
  EXPECT_EQ(products[3], 36000);  // 400 * 3 * 30
}
 
TEST(StlZipFindMapi, Found)
{
  std::vector<int> xs = {1, 2, 3, 4, 5};
  std::vector<std::string> ys = {"a", "b", "c", "d", "e"};
  
  auto result = stl_zip_find_mapi([](size_t i, auto t) -> std::optional<std::string> {
    if (std::get<0>(t) == 3)
      return "found at " + std::to_string(i);
    return std::nullopt;
  }, xs, ys);
  
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(*result, "found at 2");
}
 
TEST(StlZipFindMapi, NotFound)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  auto result = stl_zip_find_mapi([](size_t, auto t) -> std::optional<int> {
    if (std::get<0>(t) > 100)
      return std::get<0>(t);
    return std::nullopt;
  }, xs, ys);
  
  EXPECT_FALSE(result.has_value());
}
 
TEST(StlZipEqual, SameLength)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  EXPECT_TRUE(stl_zip_equal(xs, ys));
}
 
TEST(StlZipEqual, DifferentLength)
{
  std::vector<int> xs = {1, 2, 3, 4};
  std::vector<int> ys = {10, 20, 30};
  
  EXPECT_FALSE(stl_zip_equal(xs, ys));
}
 
TEST(StlZipEqualBy, AllMatch)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<int> ys = {10, 20, 30};
  
  bool result = stl_zip_equal_by([](auto t) {
    return std::get<0>(t) * 10 == std::get<1>(t);
  }, xs, ys);
  
  EXPECT_TRUE(result);
}
 
TEST(StlZipMem, Found)
{
  std::vector<int> xs = {1, 2, 3};
  std::vector<std::string> ys = {"a", "b", "c"};
  
  EXPECT_TRUE(stl_zip_mem(std::make_tuple(2, std::string("b")), xs, ys));
  EXPECT_FALSE(stl_zip_mem(std::make_tuple(2, std::string("x")), xs, ys));
}
 
TEST(StlZipAssoc, Found)
{
  std::vector<std::string> keys = {"one", "two", "three"};
  std::vector<int> values = {1, 2, 3};
  
  auto result = stl_zip_assoc(std::string("two"), keys, values);
  
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(std::get<0>(*result), "two");
  EXPECT_EQ(std::get<1>(*result), 2);
}
 
TEST(StlZipAssoc, NotFound)
{
  std::vector<std::string> keys = {"one", "two", "three"};
  std::vector<int> values = {1, 2, 3};
  
  auto result = stl_zip_assoc(std::string("four"), keys, values);
  
  EXPECT_FALSE(result.has_value());
}
 
TEST(StlZipMin, Basic)
{
  std::vector<int> xs = {3, 1, 4, 1, 5};
  std::vector<int> ys = {30, 10, 40, 10, 50};
  
  auto result = stl_zip_min(xs, ys);
  
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(std::get<0>(*result), 1);
}
 
TEST(StlZipMax, Basic)
{
  std::vector<int> xs = {3, 1, 4, 1, 5};
  std::vector<int> ys = {30, 10, 40, 10, 50};
  
  auto result = stl_zip_max(xs, ys);
  
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(std::get<0>(*result), 5);
}
 
TEST(StlZipMinMax, Basic)
{
  std::vector<int> xs = {3, 1, 4, 1, 5};
  std::vector<int> ys = {30, 10, 40, 10, 50};
  
  auto result = stl_zip_min_max(xs, ys);
  
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(std::get<0>(result->first), 1);   // min
  EXPECT_EQ(std::get<0>(result->second), 5);  // max
}
 
TEST(StlZipMinMax, Empty)
{
  std::vector<int> empty;
  std::vector<int> ys = {1, 2, 3};
  
  auto result = stl_zip_min_max(empty, ys);
  
  EXPECT_FALSE(result.has_value());
}
 
// Main
int main(int argc, char **argv)
{
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}