mal - Make a Lisp

Description

Mal is an interpreter for a subset of the Clojure programming language. Mal is implemetated from scratch in 10 different languages:

• Javascript
• Python
• Clojure
• C
• Java
• PHP
• Bash shell
• GNU Make
• mal itself
• Postscript (in-progress)

Mal is also a learning tool. Each implentation of mal is separated into 11 incremental, self-contained (and testable) steps that demonstrate core concepts of Lisp. The last step is capable of self-hosting (running the mal implemenation of mal).

The mal (make a lisp) steps are:

• step0_repl
• step1_read_print
• step2_eval
• step3_env
• step4_if_fn_do
• step5_tco
• step6_file
• step7_quote
• step8_macros
• step9_interop
• stepA_more

Mal was presented publicly for the first time in a lightning talk at Clojure West 2014 (unfortunately there is no video). See mal/clojurewest2014.mal for the presentation that was given at the conference (yes the presentation is a mal program).

Building/running implementations

Bash 4

cd bash
bash stepX_YYY.sh

C

The C implementation of mal requires the following libraries: glib, libffi6 and either the libedit or GNU readline library.

cd c
make
./stepX_YYY

Clojure

cd clojure
lein with-profile +stepX trampoline run

Java 1.7

cd java
mvn compile
mvn -quiet exec:java -Dexec.mainClass=mal.stepX_YYY
    # OR
mvn -quiet exec:java -Dexec.mainClass=mal.stepX_YYY -Dexec.args="CMDLINE_ARGS"

Javascript/Node

cd js
npm update
node stepX_YYY.js

Mal

Running the mal implementation of mal involves running stepA of one of the other implementations and passing the mal step to run as a command line argument.

cd IMPL
IMPL_STEPA_CMD ../mal/stepX_YYY.mal

GNU Make 3.81

cd make
make -f stepX_YYY.mk

PHP 5.3

cd php
php stepX_YYY.php

Postscript Level 2/3

cd ps
gs -q -dNODISPLAY stepX_YYY.ps

Python 2.X

cd python
python stepX_YYY.py