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.

Installation

LFE can be installed in different ways depending on how it is intended to be used:

• use lfetool to create projects (which will automatically have LFE as a dependency when it creates skeleton libraries, OTP apps, etc.; or
• use LFE directly in a working dir, e.g.:

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

The second alternative compiles all the files. After this has been done programs for starting the REPL and compiling LFE files can be installed with:

    $ make install

By default this will create the programs lfe, lfec and lfescript in the same directory as the erl program. This can changed by defining the make variable DESTBINDIR to point to the desired directory. So:

    $ make install DESTBINDIR=/Users/rv/bin

will put the programs in /Users/rv/bin.

REPL

If you have used lfetool to set up your project, you can simply do this to start a REPL:

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

    LFE Shell 6.0 (abort with ^G)
    >

Note that this will recompile all the deps (often useful for projects with changing dependencies). If you would prefer to only recompile code for the project itself, you can use make shell-no-deps instead.

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

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

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

and run an LFE shell script in the same style as shell scripts with:

    $ 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
• User Guide

Classic Docs

• "classic" user guide
• version history

Files with more technical details:

• lfescript.txt
• lfe_shell.txt
• lfe_macro.txt
• lfe_lib.txt
• lfe_io.txt
• lfe_gen.txt
• lfe_comp.txt
• lfe_bits.txt