Mal is a Clojure inspired Lisp interpreter.

Mal is implemented in 27 different languages:

• Bash shell
• C
• C#
• Clojure
• CoffeeScript
• Forth
• Go
• Haskell
• Java
• Javascript (Online Demo)
• Lua
• GNU Make
• mal itself
• MATLAB
• miniMAL
• Nim
• OCaml
• Perl
• PHP
• Postscript
• Python
• R
• Racket
• Ruby
• Rust
• Scala
• Visual Basic.NET

Mal is a learning tool. See the (make-a-lisp process guide). Each implementation 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 implementation 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_try
• stepA_mal

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).

cd bash
bash stepX_YYY.sh

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

cd c
make
./stepX_YYY

The C# implementation of mal has been tested on Linux using the Mono C# compiler (mcs) and the Mono runtime (version 2.10.8.1). Both are required to build and run the C# implementation.

cd cs
make
mono ./stepX_YYY.exe

cd clojure
lein with-profile +stepX trampoline run

sudo npm install -g coffee-script
cd coffee
coffee ./stepX_YYY

cd forth
gforth stepX_YYY.fs

You Go implementation of mal requires that go is installed on on the path. The implementation has been tested with Go 1.3.1.

cd go
make
./stepX_YYY

Install the Haskell compiler (ghc/ghci), the Haskell platform and either the editline package (BSD) or the readline package (GPL). On Ubuntu these packages are: ghc, haskell-platform, libghc-readline-dev/libghc-editline-dev

cd haskell
make
./stepX_YYY

The Java implementation of mal requires maven2 to build.

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"

cd js
npm update
node stepX_YYY.js

Running the Lua implementation of mal requires lua 5.1 or later, luarocks and the lua-rex-pcre library installed.

cd lua
make  # to build and link linenoise.so
./stepX_YYY.lua

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

cd make
make -f stepX_YYY.mk

Running the Nim implementation of mal requires Nim's current devel branch (0.10.3) or later, and the nre library installed.

cd nim
make
  # OR
nimble build
./stepX_YYY

cd ocaml
make
./stepX_YYY

The MATLAB implementation of mal has been tested with MATLAB version R2014a on Linux. Note that MATLAB is a commercial product. It should be fairly simple to support GNU Octave once it support classdef object syntax.

cd matlab
./stepX_YYY
matlab -nodisplay -nosplash -nodesktop -nojvm -r "stepX_YYY();quit;"
    # OR with command line arguments
matlab -nodisplay -nosplash -nodesktop -nojvm -r "stepX_YYY('arg1','arg2');quit;"

miniMAL is small Lisp interpreter implemented in less than 1024 bytes of JavaScript. To run the miniMAL implementation of mal you need to download/install the miniMAL interpreter (which requires Node.js).

cd miniMAL
# Download miniMAL and dependencies
npm install
export PATH=`pwd`/node_modules/minimal-lisp/:$PATH
# Now run mal implementation in miniMAL
miniMAL ./stepX_YYY

For readline line editing support, install Term::ReadLine::Perl or Term::ReadLine::Gnu from CPAN.

cd perl
perl stepX_YYY.pl

The PHP implementation of mal requires the php command line interface to run.

cd php
php stepX_YYY.php

The Postscript implementation of mal requires ghostscript to run. It has been tested with ghostscript 9.10.

cd ps
gs -q -dNODISPLAY -I./ stepX_YYY.ps

cd python
python stepX_YYY.py

The R implementation of mal requires R (r-base-core) to run.

cd r
make libs  # to download and build rdyncall
Rscript stepX_YYY.r

The Racket implementation of mal requires the Racket compiler/interpreter to run.

cd racket
./stepX_YYY.rb

cd ruby
ruby stepX_YYY.rb

The rust implementation of mal requires the rust compiler and build tool (cargo) to build.

cd rust
# Need patched pcre lib (should be temporary)
git clone https://github.com/kanaka/rust-pcre cadencemarseille-pcre
cargo build --release
./target/stepX_YYY

Install scala and sbt (http://www.scala-sbt.org/0.13/tutorial/Installing-sbt-on-Linux.html):

cd scala
sbt 'run-main stepX_YYY'
    # OR
sbt compile
scala -classpath target/scala*/classes stepX_YYY

The VB.NET implementation of mal has been tested on Linux using the Mono VB compiler (vbnc) and the Mono runtime (version 2.10.8.1). Both are required to build and run the VB.NET implementation.

cd vb
make
mono ./stepX_YYY.exe

The are nearly 500 generic functional tests (for all implementations) in the tests/ directory. Each step has a corresponding test file containing tests specific to that step. The runtest.py test harness uses pexpect to launch a Mal step implementation and then feeds the tests one at a time to the implementation and compares the output/return value to the expected output/return value.

To simplify the process of running tests, a top level Makefile is provided with convenient test targets.

• To run all the tests across all implementations (be prepared to wait):

make test

• To run all tests against a single implementation:

make test^IMPL

# e.g.
make test^clojure
make test^js

• To run tests for a single step against all implementations:

make test^stepX

# e.g.
make test^step2
make test^step7

• To run tests for a specifc step against a single implementation:

make test^IMPL^stepX

# e.g
make test^ruby^step3
make test^ps^step4

• To run the functional tests in self-hosted mode, you specify mal as the test implementation and use the MAL_IMPL make variable to change the underlying host language (default is JavaScript):

make MAL_IMPL=IMPL test^mal^step2

# e.g.
make test^mal^step2   # js is default
make MAL_IMPL=ruby test^mal^step2
make MAL_IMPL=python test^mal^step2

• To run performance tests against a single implementation:

make perf^IMPL

# e.g.
make perf^js

• To run performance tests against all implementations:

make perf

• To report line and byte stastics for a single implementation:

make stats^IMPL

# e.g.
make stats^js

• To report line and bytes stastics for general Lisp code (env, core and stepA):

make stats-lisp^IMPL

# e.g.
make stats-lisp^js

Mal (make-a-lisp) is licensed under the MPL 2.0 (Mozilla Public License 2.0). See LICENSE.txt for more details.