Implement frequencies_as_map

cpp/collections_module/algorithm/collections.cpp

@@ -590,3 +590,30 @@ void Collections::Flatten(mgp_list *args, mgp_func_context *ctx, mgp_func_result
         return;
     }
 }
+
+void Collections::FrequenciesAsMap(mgp_list *args, mgp_func_context *ctx, mgp_func_result *res, mgp_memory *memory) {
+  mgp::MemoryDispatcherGuard guard{memory};
+  const auto arguments = mgp::List(args);
+  auto result = mgp::Result(res);
+
+  try {
+    const auto input_list = arguments[0].ValueList();
+    std::unordered_map<mgp::Value, int64_t> frequency_map;
+
+    for (const auto &element : input_list) {
+      frequency_map[element]++;
+    }
+
+    mgp::Map result_map;
+    for (const auto &[element, count] : frequency_map) {
+      const auto key = element.ToString();
+      result_map.Insert(key, mgp::Value(count));
+    }
+
+    result.SetValue(std::move(result_map));
+
+  } catch (const std::exception &e) {
+    result.SetErrorMessage(e.what());
+    return;
+  }
+}

cpp/collections_module/algorithm/collections.hpp

@@ -90,6 +90,10 @@ constexpr std::string_view kArgumentSizePartition = "partition_size";
 constexpr std::string_view kProcedureFlatten = "flatten";
 constexpr std::string_view kArgumentListFlatten = "list";
 
+/* frequencies_as_map constants */
+constexpr std::string_view kProcedureFrequenciesAsMap = "frequencies_as_map";
+constexpr std::string_view kArgumentListFrequenciesAsMap = "coll";
+
 void SetResult(mgp::Result &result, const mgp::Value &value);
 
 void SumLongs(mgp_list *args, mgp_func_context *ctx, mgp_func_result *res, mgp_memory *memory);
@@ -128,4 +132,6 @@ void Partition(mgp_list *args, mgp_graph *memgraph_graph, mgp_result *result, mg
 
 void Flatten(mgp_list *args, mgp_func_context *ctx, mgp_func_result *res, mgp_memory *memory);
 
+void FrequenciesAsMap(mgp_list *args, mgp_func_context *ctx, mgp_func_result *res, mgp_memory *memory);
+
 }  // namespace Collections

cpp/collections_module/collections_module.cpp

@@ -75,6 +75,11 @@ extern "C" int mgp_init_module(struct mgp_module *module, struct mgp_memory *mem
                      {mgp::Parameter(Collections::kArgumentListToSet, {mgp::Type::List, mgp::Type::Any})}, module,
                      memory);
 
+    mgp::AddFunction(Collections::FrequenciesAsMap, Collections::kProcedureFrequenciesAsMap,
+                     {mgp::Parameter(Collections::kArgumentListFrequenciesAsMap, {mgp::Type::List, mgp::Type::Any})},
+                     module, memory);
+
+
     AddProcedure(
         Collections::Partition, std::string(Collections::kProcedurePartition).c_str(), mgp::ProcedureType::Read,
         {mgp::Parameter(std::string(Collections::kArgumentListPartition).c_str(), {mgp::Type::List, mgp::Type::Any}),

e2e/collections_test/test_frequencies_as_map1/test.yml

@@ -0,0 +1,5 @@
+query: >
+  RETURN collections.frequencies_as_map([1,1,2,1,3,4,1]) AS result;
+
+output:
+  - result: {"1": 4, "2": 1, "3": 1, "4": 1}

e2e/collections_test/test_frequencies_as_map2/test.yml

@@ -0,0 +1,5 @@
+query: >
+  RETURN  collections.frequencies_as_map(['a','b','a','c','b','a']) AS result;
+
+output:
+  - result: {"a": 3, "b": 2, "c": 1}

e2e/collections_test/test_frequencies_as_map3/test.yml

@@ -0,0 +1,5 @@
+query: >
+  RETURN collections.frequencies_as_map([]) AS result;
+
+output:
+  - result: {}

e2e/collections_test/test_frequencies_as_map4/test.yml

@@ -0,0 +1,5 @@
+query: >
+  RETURN collections.frequencies_as_map([1, 1, null, null, 1]) AS result;
+
+output:
+  - result: {"1": 3, "null": 2}