What is "Stack Lang Engine"

SLE (Stack Lang Engine) is a simple tool for creating stack-oriented DSL or even small programming languages.

Usage

Firstly

Of course we need to import a module, and create object with type "StackEngine"

import stack_lang_engine as sle

eng = sle.StackEngine()

Definition of words:

This is how to define/delete words in StackEngine

# Define new word
eng.add_word("print", lambda: print(eng.pop()))

# Delete word
eng.del_word("print")

How to execute text (given as string)

# If you use the default regex pattern, 
# it automatically recognizes whether it is a string or a number.
eng.exec('10 20 30 "40"')

How to create stack and APIs for it

# Create new stack, we can use "create_api" option
# to create eng.{name}_push, eng.{name}_pop() methods
# for object

eng.new_stack("stacky", create_api=True)
# now we have eng.stacky_push and eng.stacky_pop

eng.stacky_push(10)
print(eng.stacky)
eng.stacky_pop()

Usefull APIs

# Instead of writing "eng.stack.pop" or more we can use builtin
# methods like eng.(push, pop, clear)

eng.push(10) # For example

Recognizers

# We can create a new regex pattern, 
# and both the parser and the interpreter must handle it.

eng.add_recognizer(
    name="Test", # Name of recognizer
    pattern=r'Test', # Regex pattern
    on_regex=lambda val: val, # What parser should get (or do) when it parses it
    on_interpret=lambda val: print("Hello, Test!?"), # What interpreter should do when it gets it
)

# and if then we execute it will output
# "Hello, Test!?" when it interprets word
# with "Test" kind

eng.exec("Test 10 20")
print(eng.stack) # It will work correctly, so in stack only 10 and 20

How to write more short code in this engine

# For example we can set words dict instead of creating each
# word over and over

eng = sle.StackEngine(words={
    "print": lambda: print(eng.pop())
})

# You can also read the interpreter's code itself on 
# GitHub to better understand how it works.

Thanks for reading the documentation!

License

SLE is licensed under GPLv3 License