[DAPHNE-#903] Add 'groupSum()' built-in function to DaphneDSL. (#921)

This commit introduces a new `groupSum()` built-in function to DaphneDSL, enabling the creation of a `GroupOp` in DaphneIR and closes #903.

Changes Implemented
1. `groupSum()` Built-in Function in DaphneDSL:
   - Interface: `group(arg:frame, groupCols:str, ..., sumCol:str)`
   - Accepts:
     - A frame as input.
     - At least one column to group on.
     - A single column to compute the sum.
   - Aggregation Support:
     - Only supports `SUM` as the aggregation function.
3. **Test Cases**:
   - Added script-level tests to validate the functionality of the `group()` function in DaphneDSL.

doc/DaphneDSL/Builtins.md

@@ -515,6 +515,14 @@ We will support set operations such as **`intersect`**, **`merge`**, and **`exce
 
 We will support more variants of joins, including (left/right) outer joins, theta joins, anti-joins, etc.
 
+### Grouping and aggregation
+
+- **`groupSum`**`(arg:frame, grpColNames:str[, grpColNames, ...], sumColName:str)`
+
+    Groups the rows in the given frame `arg` by the specified columns `grpColNames` (at least one column) and calculates the per-group sum of the column denoted by `sumColName`.
+
+    *This built-in function is currently limited in terms of functionality (aggregation only on a single column, sum as the only aggregation function). It will be extended in the future. Meanwhile, consider using DAPHNE's `sql()` built-in function for more comprehensive grouping and aggregation support.*
+
 ### Frame label manipulation
 
 - **`setColLabels`**`(arg:frame, labels:str, ...)`

src/parser/daphnedsl/DaphneDSLBuiltins.cpp

@@ -1044,6 +1044,45 @@ antlrcpp::Any DaphneDSLBuiltins::build(mlir::Location loc, const std::string &fu
             .getResults();
     }
 
+    // --------------------------------------------------------------------
+    // Grouping and aggregation
+    // --------------------------------------------------------------------
+
+    if (func == "groupSum") {
+        // Arbitrary number of columns to group on.
+        // A single column to calculate the sum on.
+        checkNumArgsMin(loc, func, numArgs, 3);
+        mlir::Value currentFrame = args[0];
+        mlir::Value aggCol = args[numArgs - 1];
+        std::vector<mlir::Value> groupName;
+        std::vector<mlir::Value> columnName;
+        std::vector<mlir::Type> colTypes;
+
+        // set aggregaton function to SUM
+        auto aggFunc = static_cast<mlir::Attribute>(
+            mlir::daphne::GroupEnumAttr::get(builder.getContext(), mlir::daphne::GroupEnum::SUM));
+        std::vector<mlir::Attribute> functionName;
+        functionName.push_back(aggFunc);
+
+        // get group columns
+        for (size_t i = 1; i < numArgs - 1; i++) {
+            groupName.push_back(args[i]);
+        }
+
+        // get agg column
+        columnName.push_back(aggCol);
+
+        // result column types
+        mlir::Type vt = utils.unknownType;
+        for (size_t i = 0; i < groupName.size() + columnName.size(); i++) {
+            colTypes.push_back(vt);
+        }
+
+        return static_cast<mlir::Value>(builder.create<GroupOp>(loc, FrameType::get(builder.getContext(), colTypes),
+                                                                currentFrame, groupName, columnName,
+                                                                builder.getArrayAttr(functionName)));
+    }
+
     // ********************************************************************
     // Frame label manipulation
     // ********************************************************************

test/api/cli/operations/OperationsTest.cpp

@@ -40,6 +40,7 @@ MAKE_TEST_CASE("createFrame", 1)
 MAKE_TEST_CASE("ctable", 1)
 MAKE_TEST_CASE("fill", 1)
 MAKE_TEST_CASE("gemv", 1)
+MAKE_TEST_CASE("groupSum", 1)
 MAKE_TEST_CASE("idxMax", 1)
 MAKE_TEST_CASE("idxMin", 1)
 MAKE_TEST_CASE("innerJoin", 1)

test/api/cli/operations/groupSum_1.daphne

@@ -0,0 +1,8 @@
+// Grouping and sum aggregation (two grouping columns).
+
+fr = createFrame([ 11, 11, 22, 33, 33 ], [ 1, 1, 2, 3, 4 ],
+                 [ 100, 200, 300, 400, 500 ], "a", "b", "c");
+
+res = groupSum(fr, "a", "b", "c");
+
+print(res);

test/api/cli/operations/groupSum_1.txt

@@ -0,0 +1,5 @@
+Frame(4x3, [a:int64_t, b:int64_t, SUM(c):int64_t])
+11 1 300
+22 2 300
+33 3 400
+33 4 500