LFE

LFE, Lisp Flavoured Erlang, is a lisp syntax front-end to the Erlang compiler. Code produced with it is compatible with "normal" Erlang code. An LFE evaluator and shell is also included.

Building

To compile LFE, simple clone it and compile:

$ git clone https://github.com/lfe/lfe.git
$ cd lfe
$ make compile

LFE requires Erlang be installed on the system and that the erl binary is in $PATH.

Installation

Should you wish to have LFE available system-wide, you can run the following make target:

$ make install

By default this will create the programs lfe, lfec, lfedoc and lfescript in /usr/local/bin. This can be changed by defining the make variable PREFIX to point to the desired parent directory.

Note that the install target will also install the LFE man pages in the appropriate $(PREFIX)/share/man/man* directories. This can be changed by defining the make variable MANINSTDIR to point to the desired top man directory.

So:

$ make install PREFIX=/Users/rv/ MANINSTDIR=/Users/rv/man

will put the programs in /Users/rv/bin and the man pages in the /Users/rv/man/man* directories.

REPL

If you're running LFE from a git clone working dir, you can start the REPL like so after compiling:

$ ./bin/lfe
Erlang 17 (erts-6.0) [source] [64-bit] [smp:8:8] ...

LFE Shell V6.0 (abort with ^G)
>

If you have installed LFE, then you may start the REPL from any location:

$ lfe
Erlang 17 (erts-6.0) [source] [64-bit] [smp:8:8] ...

LFE Shell V6.0 (abort with ^G)
>

Likewise, you may run an LFE shell script in the same style as shell scripts with:

$ ./bin/lfe script-name script-arg-1 ...

or

$ lfe script-name script-arg-1 ...

Usage

The docs site has several places to explore that will show you how to start using LFE. However, here's a quick taste:

• start up an LFE REPL as demonstrated above
• then, do something like this:

> (* 2 (+ 1 2 3 4 5 6))
42
> (* 2 (lists:foldl #'+/2 0 (lists:seq 1 6)))
42

Docker Support

LFE now supports Docker. To get started, simply do the following, once you have Docker set up on your machine:

$ docker pull lfex/lfe

Alternatively, you could build the image yourself:

$ cd lfe
$ docker build .

Here are a couple of simple usage examples:

$ docker run lfex/lfe
42

$ docker run -i -t lfex/lfe lfe
Erlang/OTP 18 [erts-7.0] [source-4d83b58] [64-bit] [smp:8:8] ...

LFE Shell V7.0 (abort with ^G)
>

That last command will dump you into the LFE REPL on a running container of the lfex/lfe Docker image. For more information on using Docker with LFE, be sure to read the tutorial.

Documentation

• Quick Start
• LFE user guide
• version history

Files with more technical details:

• lfe.txt
• lfescript.txt
• lfe_bits.txt
• lfe_clj.txt
• lfe_comp.txt
• lfe_doc.txt
• lfe_gen.txt
• lfe_io.txt
• lfe_lib.txt
• lfe_macro.txt

If you would like to make changes to the LFE documentation and then regenerate the docs, you'll want to read the instructions here:

• Updating LFE Documentation

Join the Community

LFE on Slack, join by requesting an invite here

LFE Forum - Erlang Forums