Leex

Leex is an open source implementation of :erlang.leex.

Installation

If available in Hex, the package can be installed by adding leex to your list of dependencies in mix.exs:

def deps do
  [
    {:leex, "~> 0.1.0"}
  ]
end

Usage

defmodule Example do
  use Leex

  "INT" <~ "[0-9]+"
  "ATOM" <~ ":[a-z_]+"
  "WHITESPACE" <~ "[\s\t\n\r]"

  "{INT}" ~> {:token, {:int, token_line, String.to_integer(token_val)}}
  "{ATOM}" ~> {:token, {:atom, token_line, to_atom(token_val)}}
  "\\[" ~> {:token, {:"[", token_line}}
  "\\]" ~> {:token, {:"]", token_line}}
  "," ~> {:token, {:",", token_line}}
  "{WHITESPACE}+" ~> :skip_token

  def to_atom(<<?:, string::binary>>) do
    String.to_atom(string)
  end
end

Definition operator <~

You can create a definition with <~ operator. For instance: "INT" <~ "[0-9]+"

Rule operator ~>

You can create a rule with ~> operator. For instance: "0x{INT}" ~> {:token, {:hex_number, token_line, String.to_integer(token_val)}}

Variables

token_line: Line of token token_val: Value of token token_len: Length of token

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/leex.