Lol — Lisp On erLang

Lol — and programming is fun again.

Why?

Because the world strongly needs another programming language.

A little bit more seriously: the main idea is to make metaprogramming in erlang easier.
It is not about replacing Erlang, it is about using the two together.

Why not LFE? Lol has:

Lisp-1
Small and clean codebase (for now :))

Why not Joxa?

Joxa is not developed anymore and it uses code generation for the erlang core.

Build

$ git clone git://github.com/b0oh/lol.git
$ cd lol
$ ./rebar compile
$ echo '(defn hello [name] (io:format "Hello, ~s.~n" [name]))' > simple.lol
$ erl -pa ebin

1> lol_compiler:file("simple.lol", "ebin/simple.beam").
{ok,simple,[]}
2> simple:hello("Dima").
Hello, Dima.
ok

Example

Lol application example

Lol language

Forms

Integer: 1
Float: 1.1
Symbol: symbol
Simple string: "string"
S-expr: ()

Special forms

List: [1 2 3] expanding to (list 1 2 3)
Tuple: {1 2 3} expanding to (tuple 1 2 3)
Quote: '(1 2 3) expanding to (quote (1 2 3))
Define public function:

(defn public [arg1 arg2]
  (expr1)
  (expr2))

Define private function:

(defn- private [arg1 arg2]
  (expr1)
  (expr2))

Lambda:

(fn [arg1 arg2] (expr1) (expr2))

Let with pattern matching:

(let [{'ok file} (file:read_file "number")
      number (binary_to_integer file)]
  (io:format "Number is: ~p~n" [number]))

Let with sequence in body:

(let [{'ok file} (file:read_file "number")
      number (binary_to_integer file)]
  (do
    (file:write_file "number_copy" (integer_to_binary number))
    (io:format "Number is: ~p~n" [number])))

Case:

(case (get_coords)
  ({x y} 'ok)
  ({x y z} (do (first_expr) (second_expr))))

Call:

(call 'func)
(call 'func [arg1 arg2])
(call 'mod 'func)
(call 'mod 'func [arg1 arg2])

Apply:

(func)
(mod:func)
((fn [x] x) "some")

Plans

Full erlang forms support: float, binary, characters, strings with interpolation, records, maps, etc
Full erlang syntax support: receive, clauses for functions and lambdas, etc
Improve lol forms support: let, do, def, etc
Extended importing and name aliasing
Macroses
deftransform form for providing macroses for Erlang from Lol
Translation right in Erlang sources
stdlib
Write Lol on Lol

It is dedicated to “Let Over Lambda” and “Land of Lisp”.

Have fun.