Add support for sum expressions in evaluate()

lib/evaluator.c

@@ -4,5 +4,7 @@ int evaluate(const expression_t *expression)
 {
 	if (expression->is_number)
 		return expression->number;
-	return 0;
+	const int x = evaluate(expression->application.operands[0]);
+	const int y = evaluate(expression->application.operands[1]);
+	return x + y;
 }

tests/evaluator_tests.c

@@ -24,10 +24,106 @@ static void number_4321_is_evaluated_as_4321(void)
 	ASSERT_EQUAL(4321, result);
 }
 
+static void sum_of_14_and_31_evaluates_to_45(void)
+{
+	init_memory_pool(&pool);
+	expression_t *operand0 = allocate_expression(&pool);
+	operand0->is_number = true;
+	operand0->number = 14;
+	expression_t *operand1 = allocate_expression(&pool);
+	operand1->is_number = true;
+	operand1->number = 31;
+	expression_t *expression = allocate_expression(&pool);
+	expression->is_number = false;
+	expression->application.operator= OPERATOR_ADD;
+	expression->application.operands[0] = operand0;
+	expression->application.operands[1] = operand1;
+
+	const int result = evaluate(expression);
+	ASSERT_EQUAL(45, result);
+}
+
+static void sum_of_72_and_6_evaluates_to_78(void)
+{
+	init_memory_pool(&pool);
+	expression_t *operand0 = allocate_expression(&pool);
+	operand0->is_number = true;
+	operand0->number = 72;
+	expression_t *operand1 = allocate_expression(&pool);
+	operand1->is_number = true;
+	operand1->number = 6;
+	expression_t *expression = allocate_expression(&pool);
+	expression->is_number = false;
+	expression->application.operator= OPERATOR_ADD;
+	expression->application.operands[0] = operand0;
+	expression->application.operands[1] = operand1;
+
+	const int result = evaluate(expression);
+	ASSERT_EQUAL(78, result);
+}
+
+static void sum_of_21_and_the_sum_of_9_and_31_evaluates_to_61(void)
+{
+	init_memory_pool(&pool);
+	expression_t *operand0 = allocate_expression(&pool);
+	operand0->is_number = true;
+	operand0->number = 21;
+	expression_t *operand10 = allocate_expression(&pool);
+	operand10->is_number = true;
+	operand10->number = 9;
+	expression_t *operand11 = allocate_expression(&pool);
+	operand11->is_number = true;
+	operand11->number = 31;
+	expression_t *operand1 = allocate_expression(&pool);
+	operand1->is_number = false;
+	operand1->application.operator= OPERATOR_ADD;
+	operand1->application.operands[0] = operand10;
+	operand1->application.operands[1] = operand11;
+	expression_t *expression = allocate_expression(&pool);
+	expression->is_number = false;
+	expression->application.operator= OPERATOR_ADD;
+	expression->application.operands[0] = operand0;
+	expression->application.operands[1] = operand1;
+
+	const int result = evaluate(expression);
+	ASSERT_EQUAL(61, result);
+}
+
+static void sum_of_the_sum_of_4_and_66_and_83_evaluates_to_153(void)
+{
+	init_memory_pool(&pool);
+	expression_t *operand00 = allocate_expression(&pool);
+	operand00->is_number = true;
+	operand00->number = 4;
+	expression_t *operand01 = allocate_expression(&pool);
+	operand01->is_number = true;
+	operand01->number = 66;
+	expression_t *operand0 = allocate_expression(&pool);
+	operand0->is_number = false;
+	operand0->application.operator= OPERATOR_ADD;
+	operand0->application.operands[0] = operand00;
+	operand0->application.operands[1] = operand01;
+	expression_t *operand1 = allocate_expression(&pool);
+	operand1->is_number = true;
+	operand1->number = 83;
+	expression_t *expression = allocate_expression(&pool);
+	expression->is_number = false;
+	expression->application.operator= OPERATOR_ADD;
+	expression->application.operands[0] = operand0;
+	expression->application.operands[1] = operand1;
+
+	const int result = evaluate(expression);
+	ASSERT_EQUAL(153, result);
+}
+
 int main(void)
 {
 	TESTING_BEGIN();
 	RUN_TEST(number_1234_is_evaluated_as_1234);
 	RUN_TEST(number_4321_is_evaluated_as_4321);
+	RUN_TEST(sum_of_14_and_31_evaluates_to_45);
+	RUN_TEST(sum_of_72_and_6_evaluates_to_78);
+	RUN_TEST(sum_of_21_and_the_sum_of_9_and_31_evaluates_to_61);
+	RUN_TEST(sum_of_the_sum_of_4_and_66_and_83_evaluates_to_153);
 	TESTING_END();
 }