Lisp Flavoured Erlang (LFE)
Erlang Emacs Lisp
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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.


A quick fix has been added to compensate for some incompatibilites in
Core erlang between the old R12B and the new R13B. The fixes are found
in the file lfe_codegen.erl. For one fix code must be chosen depending
on whether the systems runs on R12B or R13B, this is the (tiny)
function c_fname/3 near the end of the file. Choose the right version
of the function. The .beam file in ebin is for R13B.

I will try to make a better fix soon. Sorry about that.


First version of Query List Comprehensions.

Add access to current macro environment through the variable $ENV
within macros which allows explicit macro expansion.

First version of match-specification generator.

Add ets/mnesia match patterns to records.

Arithmetic functions + - * / and comparison functions > >= < =< == /=
=:= =/= now take multiple arguments. This is experimental and as yet
only implemented as macros.

Handle compiler option warnings_as_errors in the same way as the
vanilla Erlang compiler.

Improved ++ macro can now be used in patterns.

List/binary comprehensions generate fewer unnecessary compiler

Added new example file with core macros implemented in LFE.

New patterns with explicit constructors! We now follow the invariant
that constructors and patterns should look the same. It is still
possible to use old patterns but 'cons' and 'list' now as as "reserved
words" like 'tuple' and 'binary'.

Allow guards with generators in list/binary comprehensions. N.B. can
cause unexpected behaviour with binary generators.


Allow literal strings in binaries, both as plain values and as values
with specs, so (binary "abc" ("åäö" utf-8)) is valid. In the second
case the spec is applied to each character. Works with lists as well.
Add big, little and native as synonyms to big-endian, little-endian
and native-endian.

Now have working Makefile, Emakefile and .app file.

Guards are now a sequence of tests, (when test test ...). The
structure of guard tests has been fixed and is now more logical as
tests. For example (if ...) is now allowed.

Add temporary fix to ensure that guards are compiled correctly. It
is less efficient but should be correct. It will be removed when no
longer necessary.

Read and output based integers.

Improve prettyprinting of defuns.

Many internal improvements.


Added macro list*.

Added a new shell command to set variables in the shell.

Cleaned up compiler options and made them more like the vanilla

Added unicode types to binaries: utf-8, utf-16 and utf-32.

Shell and compiler now print error data in LFE instead of vanilla.
Shell error reporting still pretty basic, not as "beautiful" as

Cleaned up i/o functions and added formatted output function. Still
use vanilla command characters.

All i/o goes through then module lfe_io. The functions which return
the corresponding printable string end in 1. So lfe_io:format prints
formatted output while lfe_io:format1 returns the string.

Improved pretty-printing.

Many internal improvements.

This will be the last development version for Erlang R12B-5 and older,
all future development will for R13B. If there is enough interest I
may start a separate branch for R12B.

Parameterized modules.

Added (export all) attribute to module definition.

New records which allow giving default values as in vanilla Erlang.
Records are still compatible with vanilla Erlang but now more pratical
to use. NOTE this change is not backwards compatible as syntax for
(make- ...) and (match- ...) have changed. Also added general multiple
(set- ...) macro.

(eval-when-compile ...) added as a top-level form which allows
functions to be defined when compiling the forms. These are useful for
more complex macros.

Better and more documention. The documentation is still normal text
files as Edoc and I are not in agreement on how things should work.

This is the first version with the modified internal core forms and
macro intefaces for the new CL inspired style and the older Scheme
inspired style.

Two new modules have been added:

lfe_boot allows you start Erlang with the LFE shell running and still
have ^G enabled and user_drv running. Use it as follows:

erl -noshell -noinput -s lfe_boot start

NOTE order of commands important, must be -noshell -noinput! Add -pa
to find modules if necessary.

lfe_gen is a trial interface for using LFE for dynamic code
generation. LFE is much easier to generate as an Erkang list than
Erlang forms. This module helps defining and compiling a module. Note,
that while it works, this module is very experimental and may change.