/monty

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

Primary LanguageC

MONTY

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

Learning Objectives

At the end of this project, you are expected to be able to explain to anyone, without the help of Google:

  1. What do LIFO and FIFO mean?
  2. What is a stack, and when to use it?
  3. What is a queue, and when to use it?
  4. What are the common implementations of stacks and queues?
  5. What are the most common use cases of stacks and queues?
  6. What is the proper way to use global variables?

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 */ 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 / typedef struct instruction_s { charopcode; void (*f)(stack_t **stack, unsigned int line_number); } instruction_t;

Compilation & Output

Your code will be compiled this way: $ gcc -Wall -Werror -Wextra -pedantic -std=c89 *.c -o monty Any output must be printed on stdout Any error message must be printed on stderr Here is a link to a GitHub repository that could help you making sure your errors are printed on stderr

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:

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 , followed by a new line, and exit with the status EXIT_FAILURE where is the name of the file If the file contains an invalid instruction, print the error message L<line_number>: unknown instruction , 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, …)