Monty

monty is an interpreter of Monty ByteCodes files, which is a scripting language just like Python.

About the Monty language

This is a language that contains specific instructions to manipulate data information (stacks or queues), where each instruction (called opcode) is sended per line. Files which contains Monty byte codes usually have the .m extension.

Example (file.m):

$ cat file.m
# Pushing element to the stack
push 0
push 1
push 2
# Printing all elements
pall
push 3
push 4
pop
# Rotating the stack to the bottom
rotr
pall
rotl
# Setting FIFO
queue
push 5
# Setting LIFO
stack
push 5
$

Technologies

Interpreter was written with C language
C files are compiled using gcc 4.8.4
C files are written according to the C90 standard
Tested on Ubuntu 14.04 LTS

Usage

To compile all files:

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

The synopsis of the interpreter is the following:

$ ./monty [filename]
$

To run the interpreter:

$ ./monty file.m
2
1
0
0
3
2
1
$

Features

Opcodes

monty executes the following opcodes:

Opcode	Description
`push`	Pushes an element to the stack
`pall`	Prints all the values on the stack
`pint`	Prints the value at the top of the stack
`pop`	Removes the top element of the stack
`swap`	Swaps the top two elements of the stack
`queue`	Sets the format of the data to a queue (FIFO)
`stack`	Sets the format of the data to a stack (LIFO)
`nop`	Doesn't do anything
`add`	Adds the top two elements of the stack
`sub`	Subtracts the top element of the stack from the second top element of the stack
`mul`	Multiplies the second top element of the stack with the top element of the stack
`div`	Divides the second top element of the stack by the top element of the stack
`mod`	Computes the rest of the division of the second top element of the stack by the top element of the stack
`pchar`	Prints the char at the top of the stack
`pstr`	Prints the string starting at the top of the stack
`rotl`	Rotates the stack to the top
`rotr`	Rotates the stack to the bottom

Comments, indicated with #, are not executed by the interpreter.

When a nonextistent opcode is passed, the interpreter prints an error message and stops:

$ cat errorfile.m
push 1
pint
pcx
$ ./monty errorfile.m
1
L3: unknown instruction pcx

Return value

When there is no errors, monty returns 0. Otherwise, returns 1

Authors

Gospel Isaac: Twitter - GitHub

gospelin / monty