elixir_lexer.moon

howl.util.lpeg_lexer ->

  kw = capture 'keyword', word {
    'cond','case', 'defmodule', 'defstruct', 'defmacro',
    'defprotocol', 'defexception', 'defdelegate',
    'defimpl', 'try','catch', 'do', 'end', 'after',
    'if', 'else', 'unless', 'fn','defp','def',
    'and', 'or', 'rescue', 'receive', 'alias', 'use',
    'require', 'import', 'for', 'when'
  }

  comment = capture 'comment', '#' * scan_until(eol)

  string = capture 'string', any {
    '"""' * (P(1) - P('"""'))^0 * '"""',
    span("'", "'", '\\'),
    span('"', '"', '\\')
  }

  operator = capture 'operator', S('+-*!/%^#~=<>;,.&(){}[]|?')

  hexadecimal_number =  P'0' * S'xX' * xdigit^1 * (P'.' * xdigit^1)^0 * (S'pP' * S'-+'^0 * xdigit^1)^0
  float = digit^1 * P'.' * digit^1
  number = capture 'number', any({
    hexadecimal_number * any('LL', 'll', 'ULL', 'ull')^-1,
    digit^1 * any { 'LL', 'll', 'ULL', 'ull' },
    (float + digit^1) * (S'eE' * P('-')^0 * digit^1)^0
  })

  ident = (alpha + '_')^1 * (alpha + digit + '_')^0 * S('!?')^-1
  identifier = capture 'identifier', ident
  module = capture 'class', upper^1 * any(alpha, '_', digit)^0

  special = capture 'special', any {
    'true',
    'false',
    'nil',
    ident * P(':'),
    P(':') * ident,
    P('@') * ident,
    P('~') * alpha * any {
      span('/','/','\\'),
      span('|','|','\\'),
      span('"','"','\\'),
      span('\'','\'','\\'),
      span('(',')','\\'),
      span('[',']','\\'),
      span('{','}','\\'),
      span('<','>','\\'),
    } * lower^-1
  }

  any {
    number,
    string,
    comment,
    special,
    kw,
    module,
    identifier,
    operator
  }