feat: evaluate array expression

internal/evaluator/evaluator.go

@@ -55,6 +55,8 @@ func (e *evaluator) Eval(node ast.Node) (object.Object, error) {
 		return booleanConv(node.Value), nil
 	case *ast.StringExpression:
 		return object.NewString(node.Value), nil
+	case *ast.ArrayExpression:
+		return e.evalArrayExpression(node)
 	case *ast.IfExpression:
 		return e.evalIfExpression(node)
 	case *ast.FuncExpression:
@@ -124,6 +126,21 @@ func (e *evaluator) evalIdentifierExpression(ie *ast.IdentifierExpression) (obje
 	return object.NIL, ErrIdentifierNotFound
 }
 
+func (e *evaluator) evalArrayExpression(ae *ast.ArrayExpression) (object.Object, error) {
+	elements := make([]object.Object, 0, len(ae.Elements))
+
+	for _, exp := range ae.Elements {
+		val, err := e.Eval(exp)
+		if err != nil {
+			return object.NIL, err
+		}
+
+		elements = append(elements, val)
+	}
+
+	return object.NewArray(elements...), nil
+}
+
 func (e *evaluator) evalIfExpression(ie *ast.IfExpression) (object.Object, error) {
 	condition, err := e.Eval(ie.Condition)
 	if err != nil {

internal/evaluator/evaluator_test.go

@@ -594,6 +594,25 @@ var _ = Describe("Evaluator", func() {
 			})
 		})
 
+		Context("array object", func() {
+			It("array expression", func() {
+				text = `
+				[1, 2 * 2, true];
+				`
+				expectedObject := object.NewArray(object.NewInteger(1), object.NewInteger(4), object.NewBoolean(true))
+				expectedErrors := []error{}
+
+				// parse the program
+				program, errs = p.ParseProgram(text)
+				Expect(errs).To(Equal(expectedErrors))
+
+				// evaluate the AST tree
+				obj, err := e.Eval(program)
+				Expect(err).To(BeNil())
+				Expect(obj).To(Equal(expectedObject))
+			})
+		})
+
 		Context("if conditionals", func() {
 			It("if condition is truthy", func() {
 				text = `