add

bytecodes/00.m

@@ -1 +1,5 @@
-nop
+push 1
+push 2
+push 3
+add
+pall

error.c

@@ -42,6 +42,9 @@ void error(int error_code, ...)
 		case 8:
 			fprintf(stderr, "L%d: can't swap, stack too short\n", va_arg(list, int));
 			break;
+		case 9:
+			fprintf(stderr, "L%d: can't add, stack too short\n", va_arg(list, int));
+			break;
 		default:
 			break;
 	}

helper_functions.c

@@ -20,6 +20,7 @@ void (*select_operation_func(char *op_code, int ln))(stack_t **, unsigned int)
 		{"pop", pop},
 		{"swap", swap},
 		{"nop", nop},
+		{"add", add},
 		{NULL, NULL},
 	};
 
@@ -116,7 +117,7 @@ void call_func(
 		if (
 			((head == NULL && strcmp(op_code, "pall") != 0)
 			&& strcmp(op_code, "nop") != 0)
-			|| (strcmp(op_code, "swap") == 0 && head->next == NULL))
+			|| ((strcmp(op_code, "swap") == 0 || strcmp(op_code, "add") == 0) && head->next == NULL))
 			*mode = 3;
 		func(&head, line_number);
 	}

monty.h

@@ -58,6 +58,7 @@ void print_int(stack_t **stack, unsigned int line_number);
 void pop(stack_t **stack, unsigned int line_number);
 void swap(stack_t **stack, unsigned int line_number);
 void nop(stack_t **stack, unsigned int line_number);
+void add(stack_t **stack, unsigned int line_number);
 
 /* helper functions */
 void (*select_operation_func(char *op_code, int line_number))(stack_t **, unsigned int);

stack_functions.c

@@ -36,26 +36,7 @@ void print_int(stack_t **stack, unsigned int line_number)
 		printf("%d\n", (*stack)->n);
 }
 
-/**
- * pop - pop the item from the top of stack.
- *
- * @stack: stack pointer.
- * @line_number: line number that called this funciton.
- */
-
-void pop(stack_t **stack, unsigned int line_number)
-{
-	stack_t *tmp;
 
-	if (*stack == NULL)
-		error(7, line_number);
-	else
-	{
-		tmp = *stack;
-		*stack = tmp->next;
-		free(tmp);
-	}
-}
 
 
 /**
@@ -96,3 +77,24 @@ void nop(stack_t **stack, unsigned int line_number)
 	(void)stack;
 	(void)line_number;
 }
+
+/**
+ * add - add n of top stack node to n of next node to it.
+ *
+ * @stack: the stack.
+ * @line_number: line number.
+ */
+void add(stack_t **stack, unsigned int line_number)
+{
+	stack_t *tmp = *stack;
+
+	if (*stack == NULL && (*stack)->next == NULL)
+	{
+		error(9, line_number);
+		return;
+	}
+	tmp->next->n += tmp->n;
+
+	*stack = tmp->next;
+	free(tmp);
+}

stack_operations.c

@@ -22,3 +22,24 @@ void add_to_stack(stack_t **new_node, __attribute__((unused))unsigned int ln)
 	head->next = tmp;
 	tmp->prev = head;
 }
+
+/**
+ * pop - pop the item from the top of stack.
+ *
+ * @stack: stack pointer.
+ * @line_number: line number that called this funciton.
+ */
+
+void pop(stack_t **stack, unsigned int line_number)
+{
+	stack_t *tmp;
+
+	if (*stack == NULL)
+		error(7, line_number);
+	else
+	{
+		tmp = *stack;
+		*stack = tmp->next;
+		free(tmp);
+	}
+}