module Dentaku::TokenMatchers

def self.function_token_matchers(function_name, *symbols)
  token_matchers(:open, *symbols, :close).unshift(
    TokenMatcher.send(function_name)
  )
end

def self.matcher(symbol)
  @matchers ||= [
    :datetime, :numeric, :string, :addsub, :subtract, :muldiv, :pow, :mod,
    :comparator, :comp_gt, :comp_lt, :open, :close, :comma,
    :non_close_plus, :non_group, :non_group_star, :arguments,
    :logical, :combinator, :if, :round, :roundup, :rounddown, :not,
    :anchored_minus, :math_neg_pow, :math_neg_mul
  ].each_with_object({}) do |name, matchers|
    matchers[name] = TokenMatcher.send(name)
  end
  @matchers.fetch(symbol) do
    raise "Unknown token symbol #{ symbol }"
  end
end

def self.token_matchers(*symbols)
  symbols.map { |s| matcher(s) }
end