felixayot/monty

C - Stacks, Queues - LIFO, FIFO Interpretation by Monty Language

C - Stacks, Queues - LIFO, FIFO Interpretation by Monty Language

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. In this project, I learnt how to create an interpreter for Monty ByteCode files.

Getting Started

• Ubuntu 20.04 LTS - Operating system required.

• GCC 9.4.0 - Compiler used

What’s Required

• Ubuntu Terminal or any other VM Sandbox

Installation and Usage

Clone the repository into a new directory:

$ git clone https://github.com/felixayot/monty.git

Compile with the following:

$ gcc -Wall -Werror -Wextra -pedantic -std=c89 *.c -o monty

Run the interpreter on a file:

./monty file.m

Monty Opcodes

• push

Usage: push <int>

Pushes an element to the stack.

The parameter must be an integer.

• pall

  Prints all values in the stack/queue, starting from the top.

• pint

  Prints the top value of the stack/queue.

• pop

  Removes the top element of the stack/queue.

• swap

  Swaps the top two elements of the stack/queue.

• nop

  Does not do anything.

• add

  Adds the top two elements of the stack/queue.

  The result is stored in the second element from the top and the top element is popped.

• sub

  Subtracts the top element of the stack/queue from the second element from the top.

  The result is stored in the second element from the top and the top element is removed.

• mul

  Multiplies the top two elements of the stack/queue.

  The result is stored in the second element from the top and the top element is removed.

• div

  Divides the second element from the top of the stack/queue by the top element.

  The result is stored in the second element from the top and the top element is removed.

• mod

  Computes the modulus of the second element from the top of the stack/queue divided by the top element.

  The result is stored in the second element from the top and the top element is removed.

• pchar

  Prints the character value of the top element of the stack/queue.

  The integer at the top is treated as an ASCII value.

• pstr

  Prints the string contained in the stack/queue.

  Prints characters element by element until the stack/queue is empty, a value is 0, or an error occurs.

• rotl

  Rotates the top element of the stack/queue to the bottom.

• rotr

  Rotates the bottom element of the stack/queue to the top.

• stack

  Switches a queue to stack mode.

• queue

  Switches a stack to queue mode.

  Opcodes preceded by a # are treated as comments and the corresponding line is ignored.

  Lines can be empty and can contain any number of spaces before or after an opcode and its argument (only the first opcode and/or argument is taken into account).

Examples

You can try out your own additional examples by creating a Monty file with the file extension .m and running the Monty interpreter as per the usage stated above. See below for guidance.

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:

	$ cat monty_bytecode.m
	push 1
	pint
	push 2
	pint
	push 3
	pint
	$ ./monty monty_bytecode.m
	1
	2
	3

Authors

• Felix Ayot - [email protected]

Acknowledgments

• ALX SE program provided the resources and project guidance. More information on this amazing program can be found through this link.