etnt / eml

Erlang flavored by Some ML

eml - Erlang flavored by Some ML

There are no Erlang receive,send or match expressions in EML.

Instead there is let and a type of letrec construct as well as currying. Inspired from Haskel, there is also a way to express generation of a list of integers and to represent arithmetic operators as an anonymous function. Currently, only program transformation is done, mainly inspired by the classic SPJ book.

Example 1:

fun foo =
  let val X = [1,2,3]
      val Y = [a,b,c]
      rec Zip = fn [] [] => [] | fn [A|B] [H|T] => [{A,H} | Zip(B,T)]
  in Zip(X,Y);

Example 2:

fun double L =
  let val Mult2 = map(fn X => X * 2)
  in  Mult2(L);

fun map F [H|T] =
  let val Hd = F(H)
      val Tl = map(F,T)
  in
    [Hd|Tl]
 | map _ [] = [];

Example 3:

fun f3 N = foldl(@*, 1, [1..N]);

fun foldl Fun Acc [H|T] = foldl(Fun, Fun(H,Acc), T)
 |  foldl _   Acc []    = Acc;

If you want to try it out you can either clone the eml_examples.git repo which setup the eml compiler as a rebar plugin, or set it up your self by adding the following to your rebar.config file:

{deps_dir, ["deps"]}.
{deps, [
        {eml, "0.*", 
         {git, "[e-mail]:etnt/eml.git", 
          "HEAD"}}
       ]}.
{plugins, [ rebar_eml_plugin ]}.
{plugin_dir, "deps/rebar_eml_plugin/src"}.