Add div_pos_int_ceil and split_evenly (#299)

Author: Dobiasd

include/fplus/curry_instances.autogenerated_defines

@@ -394,6 +394,7 @@ fplus_curry_define_fn_2(insert_at_idx)
 fplus_curry_define_fn_1(partition)
 fplus_curry_define_fn_1(split_at_idxs)
 fplus_curry_define_fn_1(split_every)
+fplus_curry_define_fn_1(split_evenly)
 fplus_curry_define_fn_2(split_by_token)
 fplus_curry_define_fn_1(run_length_encode_by)
 fplus_curry_define_fn_0(run_length_encode)

include/fplus/fwd_instances.autogenerated_defines

@@ -394,6 +394,7 @@ fplus_fwd_define_fn_2(insert_at_idx)
 fplus_fwd_define_fn_1(partition)
 fplus_fwd_define_fn_1(split_at_idxs)
 fplus_fwd_define_fn_1(split_every)
+fplus_fwd_define_fn_1(split_evenly)
 fplus_fwd_define_fn_2(split_by_token)
 fplus_fwd_define_fn_1(run_length_encode_by)
 fplus_fwd_define_fn_0(run_length_encode)
@@ -693,6 +694,7 @@ fplus_fwd_flip_define_fn_1(split_at_idx)
 fplus_fwd_flip_define_fn_1(partition)
 fplus_fwd_flip_define_fn_1(split_at_idxs)
 fplus_fwd_flip_define_fn_1(split_every)
+fplus_fwd_flip_define_fn_1(split_evenly)
 fplus_fwd_flip_define_fn_1(run_length_encode_by)
 fplus_fwd_flip_define_fn_1(span)
 fplus_fwd_flip_define_fn_1(aperture)

include/fplus/numeric.hpp

@@ -833,6 +833,17 @@ std::function<X(X)> divide_by(const X& x)
     };
 }
 
+// API search type: div_pos_int_ceil : (a, a) -> a
+// Positive integer division, but rounding up instead of down.
+// div_pos_int_ceil(5, 3) == 2
+template <typename X>
+static auto div_pos_int_ceil(X numerator, X denominator)
+{
+    static_assert(std::is_integral<X>::value, "type must be integral");
+    static_assert(!std::is_signed<X>::value, "type must be unsigned");
+    return numerator / denominator + (numerator % denominator != 0);
+}
+
 // API search type: histogram_using_intervals : ([(a, a)], [a]) -> [((a, a), Int)]
 // fwd bind count: 1
 // Generate a histogram of a sequence with given bins.

include/fplus/split.hpp

@@ -492,6 +492,24 @@ ContainerOut split_every(std::size_t n, const ContainerIn& xs)
         xs);
 }
 
+// API search type: split_evenly : (Int, [a]) -> [[a]]
+// fwd bind count: 1
+// Split a sequence into n similarly-sized chunks.
+// split_evenly(2, [0,1,2,3,4]) == [[0,1,2],[3,4]]
+template <typename ContainerIn,
+    typename ContainerOut = std::vector<ContainerIn>>
+ContainerOut split_evenly(std::size_t n, const ContainerIn& xs)
+{
+    const std::size_t every_n = div_pos_int_ceil(size_of_cont(xs), n);
+    return split_at_idxs<
+        std::vector<std::size_t>,
+        ContainerIn,
+        ContainerOut>(
+        numbers_step<std::size_t>(
+            every_n, size_of_cont(xs), every_n),
+        xs);
+}
+
 // API search type: split_by_token : ([a], Bool, [a]) -> [[a]]
 // fwd bind count: 2
 // Split a sequence at every segment matching a token.

include_all_in_one/include/fplus/fplus.hpp

@@ -8351,6 +8351,17 @@ std::function<X(X)> divide_by(const X& x)
     };
 }
 
+// API search type: div_pos_int_ceil : (a, a) -> a
+// Positive integer division, but rounding up instead of down.
+// div_pos_int_ceil(5, 3) == 2
+template <typename X>
+static auto div_pos_int_ceil(X numerator, X denominator)
+{
+    static_assert(std::is_integral<X>::value, "type must be integral");
+    static_assert(!std::is_signed<X>::value, "type must be unsigned");
+    return numerator / denominator + (numerator % denominator != 0);
+}
+
 // API search type: histogram_using_intervals : ([(a, a)], [a]) -> [((a, a), Int)]
 // fwd bind count: 1
 // Generate a histogram of a sequence with given bins.
@@ -10762,6 +10773,24 @@ ContainerOut split_every(std::size_t n, const ContainerIn& xs)
         xs);
 }
 
+// API search type: split_evenly : (Int, [a]) -> [[a]]
+// fwd bind count: 1
+// Split a sequence into n similarly-sized chunks.
+// split_evenly(2, [0,1,2,3,4]) == [[0,1,2],[3,4]]
+template <typename ContainerIn,
+    typename ContainerOut = std::vector<ContainerIn>>
+ContainerOut split_evenly(std::size_t n, const ContainerIn& xs)
+{
+    const std::size_t every_n = div_pos_int_ceil(size_of_cont(xs), n);
+    return split_at_idxs<
+        std::vector<std::size_t>,
+        ContainerIn,
+        ContainerOut>(
+        numbers_step<std::size_t>(
+            every_n, size_of_cont(xs), every_n),
+        xs);
+}
+
 // API search type: split_by_token : ([a], Bool, [a]) -> [[a]]
 // fwd bind count: 2
 // Split a sequence at every segment matching a token.
@@ -15094,6 +15123,7 @@ fplus_curry_define_fn_2(insert_at_idx)
 fplus_curry_define_fn_1(partition)
 fplus_curry_define_fn_1(split_at_idxs)
 fplus_curry_define_fn_1(split_every)
+fplus_curry_define_fn_1(split_evenly)
 fplus_curry_define_fn_2(split_by_token)
 fplus_curry_define_fn_1(run_length_encode_by)
 fplus_curry_define_fn_0(run_length_encode)
@@ -15702,6 +15732,7 @@ fplus_fwd_define_fn_2(insert_at_idx)
 fplus_fwd_define_fn_1(partition)
 fplus_fwd_define_fn_1(split_at_idxs)
 fplus_fwd_define_fn_1(split_every)
+fplus_fwd_define_fn_1(split_evenly)
 fplus_fwd_define_fn_2(split_by_token)
 fplus_fwd_define_fn_1(run_length_encode_by)
 fplus_fwd_define_fn_0(run_length_encode)
@@ -16001,6 +16032,7 @@ fplus_fwd_flip_define_fn_1(split_at_idx)
 fplus_fwd_flip_define_fn_1(partition)
 fplus_fwd_flip_define_fn_1(split_at_idxs)
 fplus_fwd_flip_define_fn_1(split_every)
+fplus_fwd_flip_define_fn_1(split_evenly)
 fplus_fwd_flip_define_fn_1(run_length_encode_by)
 fplus_fwd_flip_define_fn_1(span)
 fplus_fwd_flip_define_fn_1(aperture)

test/numeric_test.cpp

@@ -286,6 +286,14 @@ TEST_CASE("numeric_test - ceil_to_int_mult")
     REQUIRE_EQ(ceil_to_int_mult(1, 1), 1);
 }
 
+TEST_CASE("numeric_test - div_pos_int_ceil")
+{
+    using namespace fplus;
+    const std::uint64_t numerator = 5;
+    const std::uint64_t denominator = 3;
+    REQUIRE_EQ(div_pos_int_ceil(numerator, denominator), 2);
+}
+
 TEST_CASE("numeric_test - reference_interval")
 {
     using namespace fplus;

test/split_test.cpp

@@ -91,6 +91,9 @@ TEST_CASE("split_test - split functions")
     REQUIRE_EQ(split_at_idx(2, xs), std::make_pair(IntVector({ 1, 2 }), IntVector({ 2, 3, 2 })));
     REQUIRE_EQ(partition(is_even_int, xs), std::make_pair(IntVector({ 2, 2, 2 }), IntVector({ 1, 3 })));
     REQUIRE_EQ(split_every(2, xs), IntVectors({ { 1, 2 }, { 2, 3 }, { 2 } }));
+    REQUIRE_EQ(split_evenly(1, xs), IntVectors({ { 1, 2, 2, 3, 2 } }));
+    REQUIRE_EQ(split_evenly(2, xs), IntVectors({ { 1, 2, 2 }, { 3, 2 } }));
+    REQUIRE_EQ(split_evenly(3, xs), IntVectors({ { 1, 2 }, { 2, 3 }, { 2 } }));
     auto splittedAt1And3 = split_at_idxs(IdxVector({ 1, 3 }), xs);
     IntVectors splittedAt1And3Dest = { IntVector({ 1 }), IntVector({ 2, 2 }), IntVector({ 3, 2 }) };
     REQUIRE_EQ(splittedAt1And3, splittedAt1And3Dest);