Lua to Python

This is a project where I attempt to convert Lua to Python, by transforming Lua into Python AST and then running it.

Current status

• Variable assignments, basic datatypes and comparisons, if statements, while loops and functions are working.

Getting started

• pip install -r requirements.txt

Usage: compile.py [OPTIONS] SOURCE_FILE

Options:
  --strip_comments INTEGER  Remove comments from tokens
  --tokens INTEGER          Show tokens generated by lexer
  --ast INTEGER             Show the internal AST (later transformed to Python
                            AST
  --py_ast INTEGER          Show Python AST
  --py_code INTEGER         Show generated Python code
  --help                    Show this message and exit.

Example: ./compile.py --strip-comments=1 examples/functions.lua

Roadmap

• [x] Single line comments
• [x] Multiline comments
• [x] Numbers
• [x] Strings
• [x] Nil types
• [x] Variable assignments
• [x] Addition
• [x] Multiplication
• [x] If statements
• [x] Nested if statements
• [x] ~= operator
• [x] == operator
• [x] while keyword
• [x] Concat strings with ..
• [x] Subtract values
• [x] >= operator
• [x] <= operator
• [x] Boolean types
• [x] function declarations
• [x] return
• [x] not logical operator
• [x] bool expression in comparison
• [x] % operator
• [x] / operator
• [x] or logical operator
• [x] and logical operator
• [x] Assign function return to variable
• [x] Double number support
• [x] Negative values
• [x] Anonymous functions
• [x] Variables with numbers in name
• [x] Table datatype
• [x] Support for accessing Table properties
• [x] Support for lteral notation (['@!#']) in Table
• [x] List as argument to Table constructor
• [x] # operator for retrieving Table/String length
• [x] Iterator for Table using pairs/ipairs
• [x] _G for globals access
• [x] for keyword
• [x] Add multiple assignment support (x, y, z = 1, 2, 3)
• [x] Add multiple assignment support in for loop target+iterator
• [x] Add multiline line support to anonymous functions
• [ ] repeat keyword
• [ ] Short circuit / tenary operator
• [ ] local variables
• [ ] Numbers beginning with . (ex .123)
• [ ] Undefined variables should return nil
• [ ] Dot property syntax in Table for string keys
• [ ] Function calls with single params should not require parens
• [ ] Metatable support for tables
• [ ] BUG: Function cannot call itself
• [ ] BUG: Function declaration in nested Table
• [ ] BUG: Nested attribute retrival with ["random"]["random2"]
• [ ] BUG: Decimal type key in Table
• [ ] BUG: Table construct in function (ex: pairs({a=1, b=2, c=3})

References

• https://drew.ltd/blog/posts/2020-7-18.html - Many thanks for Drew and his excellent articles on how to build a programming language
• https://greentreesnakes.readthedocs.io/en/latest/
• https://github.com/python/cpython/blob/master/Lib/ast.py
• https://learnxinyminutes.com/docs/lua/