functions with arguments

compiler/compiler.go

@@ -265,6 +265,10 @@ func (c *Compiler) Compile(node ast.Node) error {
 	case *ast.FunctionLiteral:
 		c.enterScope()
 
+		for _, p := range node.Parameters {
+			c.symbolTable.Define(p.Value)
+		}
+
 		err := c.Compile(node.Body)
 		if err != nil {
 			return err
@@ -280,7 +284,11 @@ func (c *Compiler) Compile(node ast.Node) error {
 		numLocals := c.symbolTable.numDefinitions
 		instructions := c.leaveScope()
 
-		compiledFn := &object.CompiledFunction{Instructions: instructions, NumLocals: numLocals}
+		compiledFn := &object.CompiledFunction{
+			Instructions:  instructions,
+			NumLocals:     numLocals,
+			NumParameters: len(node.Parameters),
+		}
 		c.emit(code.OpConstant, c.addConstant(compiledFn))
 
 	case *ast.ReturnStatement:
@@ -297,7 +305,14 @@ func (c *Compiler) Compile(node ast.Node) error {
 			return err
 		}
 
-		c.emit(code.OpCall)
+		for _, a := range node.Arguments {
+			err := c.Compile(a)
+			if err != nil {
+				return err
+			}
+		}
+
+		c.emit(code.OpCall, len(node.Arguments))
 
 	}
 

compiler/compiler_test.go

@@ -562,7 +562,7 @@ func TestFunctionCalls(t *testing.T) {
 			},
 			expectedInstructions: []code.Instructions{
 				code.Make(code.OpConstant, 1), // The compiled function
-				code.Make(code.OpCall),
+				code.Make(code.OpCall, 0),
 				code.Make(code.OpPop),
 			},
 		},
@@ -582,7 +582,57 @@ func TestFunctionCalls(t *testing.T) {
 				code.Make(code.OpConstant, 1), // The compiled function
 				code.Make(code.OpSetGlobal, 0),
 				code.Make(code.OpGetGlobal, 0),
-				code.Make(code.OpCall),
+				code.Make(code.OpCall, 0),
+				code.Make(code.OpPop),
+			},
+		},
+		{
+			input: `
+            let oneArg = fn(a) { a };
+            oneArg(24);
+            `,
+			expectedConstants: []interface{}{
+				[]code.Instructions{
+					code.Make(code.OpGetLocal, 0),
+					code.Make(code.OpReturnValue),
+				},
+				24,
+			},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpConstant, 0),
+				code.Make(code.OpSetGlobal, 0),
+				code.Make(code.OpGetGlobal, 0),
+				code.Make(code.OpConstant, 1),
+				code.Make(code.OpCall, 1),
+				code.Make(code.OpPop),
+			},
+		},
+		{
+			input: `
+            let manyArg = fn(a, b, c) { a; b; c };
+            manyArg(24, 25, 26);
+            `,
+			expectedConstants: []interface{}{
+				[]code.Instructions{
+					code.Make(code.OpGetLocal, 0),
+					code.Make(code.OpPop),
+					code.Make(code.OpGetLocal, 1),
+					code.Make(code.OpPop),
+					code.Make(code.OpGetLocal, 2),
+					code.Make(code.OpReturnValue),
+				},
+				24,
+				25,
+				26,
+			},
+			expectedInstructions: []code.Instructions{
+				code.Make(code.OpConstant, 0),
+				code.Make(code.OpSetGlobal, 0),
+				code.Make(code.OpGetGlobal, 0),
+				code.Make(code.OpConstant, 1),
+				code.Make(code.OpConstant, 2),
+				code.Make(code.OpConstant, 3),
+				code.Make(code.OpCall, 3),
 				code.Make(code.OpPop),
 			},
 		},