0x19. C - Stacks, Queues - LIFO, FIFO

Stack: In the pushdown stacks only two operations are allowed: push the item into the stack, and pop the item out of the stack.
Queues :An excellent example of a queue is a line of students in the food court of the UC. New additions to a line made to the back of the queue, while removal (or serving) happens in the front. In the queue only two operations are allowed enqueue and dequeue.

General

What do LIFO and FIFO mean
What is a stack, and when to use it
What is a queue, and when to use it
What are the common implementations of stacks and queues
What are the most common use cases of stacks and queues
What is the proper way to use global variables
How to work with git submodules

Data structures

Please use the following data structures for this project. Don’t forget to include them in your header file.

/**
 * struct stack_s - doubly linked list representation of a stack (or queue)
 * @n: integer
 * @prev: points to the previous element of the stack (or queue)
 * @next: points to the next element of the stack (or queue)
 *
 * Description: doubly linked list node structure
 * for stack, queues, LIFO, FIFO Holberton project
 */
typedef struct stack_s
{
        int n;
        struct stack_s *prev;
        struct stack_s *next;
} stack_t;

/**
 * struct instruction_s - opcode and its function
 * @opcode: the opcode
 * @f: function to handle the opcode
 *
 * Description: opcode and its function
 * for stack, queues, LIFO, FIFO Holberton project
 */
typedef struct instruction_s
{
        char *opcode;
        void (*f)(stack_t **stack, unsigned int line_number);
} instruction_t;

Compilation & Output

$ gcc -Wall -Werror -Wextra -pedantic *.c -o monty

Tests

We strongly encourage you to work all together on a set of tests

The Monty language Monty 0.98 is a scripting language that is first compiled into Monty byte codes (Just like Python). It relies on a unique stack, with specific instructions to manipulate it. The goal of this project is to create an interpreter for Monty ByteCodes files.
Monty byte code files Files containing Monty byte codes usually have the .m extension. Most of the industry uses this standard but it is not required by the specification of the language. There is not more than one instruction per line. There can be any number of spaces before or after the opcode and its argument:

julien@ubuntu:~/0x19-stacks_queues_lifo_fifo$ cat -e bytecodes/000.m
push 0$
push 1$
push 2$
  push 3$
                   pall    $
push 4$
    push 5    $
      push    6        $
pall$
julien@ubuntu:~/0x19-stacks_queues_lifo_fifo$

Monty byte code files can contain blank lines (empty or made of spaces only, and any additional text after the opcode or its required argument is not taken into account:

julien@ubuntu:~/0x19-stacks_queues_lifo_fifo$ cat -e bytecodes/001.m
push 0 Push 0 onto the stack$
push 1 Push 1 onto the stack$
$
push 2$
  push 3$
                   pall    $
$
$
                           $
push 4$
$
    push 5    $
      push    6        $
$
pall This is the end of our program. Monty is awesome!$
julien@ubuntu:~/0x19-stacks_queues_lifo_fifo$

The monty program

Usage: monty file
- where file is the path to the file containing Monty byte code
If the user does not give any file or more than one argument to your program, print the error message USAGE: monty file, followed by a new line, and exit with the status EXIT_FAILURE
If, for any reason, it’s not possible to open the file, print the error message Error: Can't open file <file>, followed by a new line, and exit with the status EXIT_FAILURE
- where <file> is the name of the file
If the file contains an invalid instruction, print the error message L<line_number>: unknown instruction <opcode>, followed by a new line, and exit with the status EXIT_FAILURE
- where is the line number where the instruction appears.
- Line numbers always start at 1
The monty program runs the bytecodes line by line and stop if either:
- it executed properly every line of the file
- it finds an error in the file
- an error occured.
If you can’t malloc anymore, print the error message Error: malloc failed, followed by a new line, and exit with status EXIT_FAILURE.
You have to use malloc and free and are not allowed to use any other function from man malloc (realloc, calloc, …)

Main functions

monty.h: add advanced functions.
int main(): Main function.
void add(): Adds the top two elements of the stack.
void sub(): Subtracts the top element of the stack from the second top element of the stack.
void mul(): Multiplies the second top element of the stack with the top element of the stack.
void div(): Divides the second top element of the stack by the top element of the stack.
void mod(): Computes the rest of the division of the second top element of the stack by the top element of the stack.
void swap(): Swaps the top two elements of the stack.
void nop(): Does nothing.
void pall(): Prints all the values on the stack, starting from the top of the stack.
void push(): Pushes an element to the stack.
void pint(): Prints the value at the top of the stack, followed by a new line.
void pop(): Removes the top element of the stack.
void make_free_error(): Free memory stack

Authors

Maribel Serna A
Luis Diaz

luiseduardiazc / monty