A MAL-to-Python Compiler

Make a Lisp (MAL) is a Lisp programming language designed for educational purposes, aimed at teaching people how to implement a programming language from scratch. It currently has multiple implementations across various programming languages, including python3, which interprets MAL code but does not include a compiler.

This project is a fork of an earlier version of the official python3 implementation, with additional enhancements to include a compiler. As a result, it achieves performance approximately 16 times faster than the original interpreter. It has been officially recognized and included on the MAL project's README page. The source code for this implementation is located in ./impls/python-compile/.

Examples

$ ./impls/python-compile/run
user> (+ 1 1)
; => 2
user> (= 0 0)
; = > true
user> (= 0 1)
; => false

user> (def! fib (fn* (N) (if (= N 0) 1 (if (= N 1) 1 (+ (fib (- N 1)) (fib (- N 2)))))))
user> fib
; => <function _blk_0.<locals>.blk_0.<locals>.blk_0_fn at 0x103cb5a80>
user> (fib 10)
; => 89
user> (let* (fib 8) (- 24 8))
; => 16

user> (defmacro! unless (fn* (pred a b) `(if ~pred ~b ~a)))
; => nil
user> (unless (= 0 1) 7 8)
; => 7

Interopt with Underlying Python

user> ;()
Python 3.12.8 (main, Dec  8 2024, 03:59:45) [Clang 14.0.0 (clang-1400.0.29.202)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
[PYTHON]> _lisp_prompt = 'lisp> '
[PYTHON]> LISP()
LISP()
lisp> (+ 1 1)
2

~16 Times Faster Than The Interpreted Version

Per the official performance test suite, python-compile is near 16 times faster than the interpreted version.

[./mal]$ make "perf^python"
----------------------------------------------
Performance test for python:
Running: env STEP=stepA_mal MAL_IMPL=js python_MODE=python ../python/run ../tests/perf1.mal
Elapsed time: 1 msecs
Running: env STEP=stepA_mal MAL_IMPL=js python_MODE=python ../python/run ../tests/perf2.mal
Elapsed time: 4 msecs
Running: env STEP=stepA_mal MAL_IMPL=js python_MODE=python ../python/run ../tests/perf3.mal
iters over 10 seconds: 9311

[./mal]$ make "perf^python-compile"
----------------------------------------------
Performance test for python-compile:
Running: env STEP=stepA_mal MAL_IMPL=js ../python-compile/run ../tests/perf1.mal
Running: env STEP=stepA_mal MAL_IMPL=js ../python-compile/run ../tests/perf2.mal
Running: env STEP=stepA_mal MAL_IMPL=js ../python-compile/run ../tests/perf3.mal
iters over 10 seconds: 148519

Passed All Substantial¹ Official Tests

Quickly test them by running:

[./mal]$ \
for ((i=2; i<=10; i++)); do
    [ $i -eq 10 ] && make "test^python-compile^stepA" || make "test^python-compile^step${i}"
    [ $? -ne 0 ] && { echo "Error occurred. Breaking loop."; break; }
done

Footnotes

1. Passed test suites: 2, 3, 4, 5, 6, 7, 8, 9, A. ↩