Mal is a Clojure inspired Lisp interpreter.

Mal is implemented in 64 languages:

• Ada
• GNU awk
• Bash shell
• BASIC (C64 and QBasic)
• C
• C++
• C#
• ChucK
• Common Lisp
• Clojure
• CoffeeScript
• Crystal
• D
• Dart
• Elixir
• Emacs Lisp
• Erlang
• ES6 (ECMAScript 6 / ECMAScript 2015)
• F#
• Factor
• Forth
• Go
• Groovy
• GNU Guile
• Haskell
• Haxe
• Io
• Java
• JavaScript (Online Demo)
• Julia
• Kotlin
• Logo
• Lua
• GNU Make
• mal itself
• MATLAB
• miniMAL
• Nim
• Object Pascal
• Objective C
• OCaml
• Perl
• Perl 6
• PHP
• Picolisp
• PL/pgSQL (Postgres)
• PL/SQL (Oracle)
• Postscript
• PowerShell
• Python
• RPython
• R
• Racket
• Ruby
• Rust
• Scala
• Skew
• Swift
• Swift 3
• Tcl
• TypeScript
• VHDL
• Vimscript
• 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 examples/clojurewest2014.mal for the presentation that was given at the conference (yes the presentation is a mal program). At Midwest.io 2015, Joel Martin gave a presentation on Mal titled "Achievement Unlocked: A Better Path to Language Learning". Video, Slides.

If you are interesting in creating a mal implementation (or just interested in using mal for something), please drop by the #mal channel on freenode. In addition to the make-a-lisp process guide there is also a mal/make-a-lisp FAQ where I attempt to answer some common questions.

The simplest way to run any given implementation is to use docker. Every implementation has a docker image pre-built with language dependencies installed. You can launch the REPL using a convenience target in the top level Makefile (where IMPL is the implementation directory name and stepX is the step to run):

make DOCKERIZE=1 "repl^IMPL^stepX"
    # OR stepA is the default step:
make DOCKERIZE=1 "repl^IMPL"

The Ada implementation was created by Chris Moore

The Ada implementation was developed with GNAT 4.9 on debian. It also compiles unchanged on windows if you have windows versions of git, GNAT and (optionally) make. There are no external dependencies (readline not implemented).

cd ada
make
./stepX_YYY

The GNU awk implementation was created by Miutsuru kariya

The GNU awk implementation of mal has been tested with GNU awk 4.1.1.

cd gawk
gawk -O -f stepX_YYY.awk

cd bash
bash stepX_YYY.sh

The BASIC implementation uses a preprocessor that can generate BASIC code that is compatible with both C64 BASIC (CBM v2) and QBasic. The C64 mode has been tested with cbmbasic (the patched version is currently required to fix issues with line input) and the QBasic mode has been tested with qb64.

Generate C64 code and run it using cbmbasic:

cd basic
make stepX_YYY.bas
STEP=stepX_YYY ./run

Generate QBasic code and load it into qb64:

cd basic
make MODE=qbasic stepX_YYY.bas
./qb64 stepX_YYY.bas

Thanks to Steven Syrek for the original inspiration for this implementation.

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

cd c
make
./stepX_YYY

The C++ implementation was created by Stephen Thirlwall (sdt)

The C++ implementation of mal requires g++-4.9 or clang++-3.5 and a readline compatible library to build. See the cpp/README.md for more details:

cd cpp
make
    # OR
make CXX=clang++-3.5
./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

The ChucK implementation was created by Vasilij Schneidermann

The ChucK implementation has been tested with ChucK 1.3.5.2.

cd chuck
./run

The Common Lisp implementation was created by Iqbal Ansari

The implementation has been tested with SBCL, CCL, CMUCL, GNU CLISP, ECL and Allegro CL on Ubuntu 16.04 and Ubuntu 12.04, see the [README][common-lisp/README.org] for more details. Provided you have the dependencies mentioned installed, do the following to run the implementation

cd common-lisp
make
./run

For the most part the Clojure implementation requires Clojure 1.5, however, to pass all tests, Clojure 1.8.0-RC4 is required.

cd clojure
lein with-profile +stepX trampoline run

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

The Crystal implementation of mal was created by Linda_pp

The Crystal implementation of mal has been tested with Crystal 0.18.4.

cd crystal
crystal run ./stepX_YYY.cr
    # OR
make   # needed to run tests
./stepX_YYY

The D implementation was created by Dov Murik

The D implementation of mal was tested with GDC 4.8. It requires the GNU readline library.

cd d
make
./stepX_YYY

The Dart implementation was created by Harry Terkelsen

The Dart implementation has been tested with Dart 1.20.

cd dart
dart ./stepX_YYY

The Emacs Lisp implementation was created by Vasilij Schneidermann

The Emacs Lisp implementation of mal has been tested with Emacs 24.3 and 24.5. While there is very basic readline editing (<backspace> and C-d work, C-c cancels the process), it is recommended to use rlwrap.

cd elisp
emacs -Q --batch --load stepX_YYY.el
# with full readline support
rlwrap emacs -Q --batch --load stepX_YYY.el

The Elixir implementation was created by Martin Ek (ekmartin)

The Elixir implementation of mal has been tested with Elixir 1.0.5.

cd elixir
mix stepX_YYY
# Or with readline/line editing functionality:
iex -S mix stepX_YYY

The Erlang implementation was created by Nathan Fiedler (nlfiedler)

The Erlang implementation of mal requires Erlang/OTP R17 and rebar to build.

cd erlang
make
    # OR
MAL_STEP=stepX_YYY rebar compile escriptize # build individual step
./stepX_YYY

The ES6 implementation uses the babel compiler to generate ES5 compatible JavaScript. The generated code has been tested with Node 0.12.4.

cd es6
make
node build/stepX_YYY.js

The F# implementation was created by Peter Stephens (pstephens)

The F# implementation of mal has been tested on Linux using the Mono F# compiler (fsharpc) and the Mono runtime (version 3.12.1). The mono C# compiler (mcs) is also necessary to compile the readline dependency. All are required to build and run the F# implementation.

cd fsharp
make
mono ./stepX_YYY.exe

The Factor implementation was created by Jordan Lewis (jordanlewis)

The Factor implementation of mal has been tested with Factor 0.97 (factorcode.org).

cd factor
FACTOR_ROOTS=. factor -run=stepX_YYY

The Forth implementation was created by Chris Houser (chouser)

cd forth
gforth stepX_YYY.fs

The 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

The Groovy implementation of mal requires Groovy to run and has been tested with Groovy 1.8.6.

cd groovy
make
groovy ./stepX_YYY.groovy

The Guile implementation was created by Mu Lei (NalaGinrut).

cd guile
guile -L ./ stepX_YYY.scm

The Haskell implementation requires the ghc compiler version 7.10.1 or later and also the Haskell parsec and readline (or editline) packages.

cd haskell
make
./stepX_YYY

The Haxe implementation of mal requires Haxe version 3.2 to compile. Four different Haxe targets are supported: Neko, Python, C++, and JavaScript.

cd haxe
# Neko
make all-neko
neko ./stepX_YYY.n
# Python
make all-python
python3 ./stepX_YYY.py
# C++
make all-cpp
./cpp/stepX_YYY
# JavaScript
make all-js
node ./stepX_YYY.js

The Io implementation was created by Dov Murik

The Io implementation of mal has been tested with Io version 20110905.

cd io
io ./stepX_YYY.io

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

The Julia implementation of mal requires Julia 0.4.

cd julia
julia stepX_YYY.jl

The Kotlin implementation was created by Javier Fernandez-Ivern

The Kotlin implementation of mal has been tested with Kotlin 1.0.

cd kotlin
make
java -jar stepX_YYY.jar

The Logo implementation was created by Dov Murik

The Logo implementation of mal has been tested with UCBLogo 6.0.

cd logo
logo stepX_YYY.lg

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

The Nim implementation was created by Dennis Felsing (def-)

The Nim implementation of mal has been tested with Nim 0.15.2.

cd nim
make
  # OR
nimble build
./stepX_YYY

The Object Pascal implementation of mal has been built and tested on Linux using the Free Pascal compiler version 2.6.2 and 2.6.4.

cd objpascal
make
./stepX_YYY

The Objective C implementation of mal has been built and tested on Linux using clang/LLVM 3.6. It has also been built and tested on OS X using XCode 7.

cd objc
make
./stepX_YYY

The OCaml implementation was created by Chris Houser (chouser)

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 Perl 6 implementation was created by Hinrik Örn Sigurðsson

The Perl 6 implementation was tested on Rakudo Perl 6 2016.04.

cd perl6
perl6 stepX_YYY.pl

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

cd php
php stepX_YYY.php

The Picolisp implementation was created by Vasilij Schneidermann

The Picolisp implementation requires libreadline and Picolisp 3.1.11 or later.

cd pil
./run

The PL/pgSQL implementation of mal requires a running Postgres server (the "kanaka/mal-test-plpgsql" docker image automatically starts a Postgres server). The implementation connects to the Postgres server and create a database named "mal" to store tables and stored procedures. The wrapper script uses the psql command to connect to the server and defaults to the user "postgres" but this can be overridden with the PSQL_USER environment variable. A password can be specified using the PGPASSWORD environment variable. The implementation has been tested with Postgres 9.4.

cd plpgsql
./wrap.sh stepX_YYY.sql
    # OR
PSQL_USER=myuser PGPASSWORD=mypass ./wrap.sh stepX_YYY.sql

The PL/pgSQL implementation of mal requires a running Oracle DB server (the "kanaka/mal-test-plsql" docker image automatically starts an Oracle Express server). The implementation connects to the Oracle server to create types, tables and stored procedures. The default SQLPlus logon value (username/password@connect_identifier) is "system/oracle" but this can be overridden with the ORACLE_LOGON environment variable. The implementation has been tested with Oracle Express Edition 11g Release 2. Note that any SQLPlus connection warnings (user password expiration, etc) will interfere with the ability of the wrapper script to communicate with the DB.

cd plsql
./wrap.sh stepX_YYY.sql
    # OR
ORACLE_LOGON=myuser/mypass@ORCL ./wrap.sh stepX_YYY.sql

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

The PowerShell implementation of mal requires the PowerShell script language. It has been tested with PowerShell 6.0.0 Alpha 9 on Linux.

cd powershell
powershell ./stepX_YYY.ps1

cd python
python stepX_YYY.py

You must have rpython on your path (included with pypy).

cd rpython
make        # this takes a very long time
./stepX_YYY

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.rkt

cd ruby
ruby stepX_YYY.rb

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

cd rust
cargo run --release --bin 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 Skew implementation was created by Dov Murik

The Skew implementation of mal has been tested with Skew 0.7.42.

cd skew
make
node stepX_YYY.js

The Swift implementation was created by Keith Rollin

The Swift implementation of mal requires the Swift 2.0 compiler (XCode 7.0) to build. Older versions will not work due to changes in the language and standard library.

cd swift
make
./stepX_YYY

The Swift 3 implementation of mal requires the Swift 3.0 compiler. It has been tested with Swift 3 Preview 3.

cd swift3
make
./stepX_YYY

The Tcl implementation was created by Dov Murik

The Tcl implementation of mal requires Tcl 8.6 to run. For readline line editing support, install tclreadline.

cd tcl
tclsh ./stepX_YYY.tcl

The TypeScript implementation was created by vvakame

The TypeScript implementation of mal requires the TypeScript 2.2 compiler. It has been tested with Node.js v6.

cd ts
make
node ./stepX_YYY.js

The VHDL implementation was created by Dov Murik

The VHDL implementation of mal has been tested with GHDL 0.29.

cd vhdl
make
./run_vhdl.sh ./stepX_YYY

The Vimscript implementation was created by Dov Murik

The Vimscript implementation of mal requires Vim 8.0 to run.

cd vimscript
./run_vimscript.sh ./stepX_YYY.vim

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 over 600 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 launches 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 specific 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 start the REPL of an implementation in a specific step:

make "repl^IMPL^stepX"

# e.g
make "repl^ruby^step3"
make "repl^ps^step4"

• If you omit the step, then stepA is used:

make "repl^IMPL"

# e.g
make "repl^ruby"
make "repl^ps"

• To start the REPL of the self-hosted implementation, specify mal as the REPL implementation and use the MAL_IMPL make variable to change the underlying host language (default is JavaScript):

make MAL_IMPL=IMPL "repl^mal^stepX"

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

Warning: These performance tests are neither statistically valid nor comprehensive; runtime performance is a not a primary goal of mal. If you draw any serious conclusions from these performance tests, then please contact me about some amazing oceanfront property in Kansas that I'm willing to sell you for cheap.

• 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 statistics for a single implementation:

make "stats^IMPL"

# e.g.
make "stats^js"

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

make "stats-lisp^IMPL"

# e.g.
make "stats-lisp^js"

Every implementation directory contains a Dockerfile to create a docker image containing all the dependencies for that implementation. In addition, the top-level Makefile contains support for running the tests target (and perf, stats, repl, etc) within a docker container for that implementation by passing "DOCKERIZE=1" on the make command line. For example:

make DOCKERIZE=1 "test^js^step3"

Existing implementations already have docker images built and pushed to the docker registry. However, if you wish to build or rebuild a docker image locally, the toplevel Makefile provides a rule for building docker images:

make "docker-build^IMPL"

Notes:

• Docker images are named "kanaka/mal-test-IMPL"
• JVM-based language implementations (Groovy, Java, Clojure, Scala): you will probably need to run these implementations once manually first (make DOCKERIZE=1 "repl^IMPL")before you can run tests because runtime dependencies need to be downloaded to avoid the tests timing out. These dependencies are download to dot-files in the /mal directory so they will persist between runs.

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