# encoding: utf-8

module Unparser
  # All unparser constants maybe included in other libraries.
  module Constants

    # Return frozen symbol set from enumerable
    #
    # @param [Enumerable]
    #
    # @return [Set<Symbol>]
    #
    # @api private
    #
    def self.symbol_set(enumerable)
      enumerable.map(&:to_sym).freeze
    end
    private_class_method :symbol_set

    # All unary operators of the ruby language
    UNARY_OPERATORS = symbol_set %w(
      ! ~ -@ +@
    )

    # All binary operators of the ruby language
    BINARY_OPERATORS = symbol_set %w(
      + - * / & | && || << >> ==
      === != <= < <=> > >= =~ !~ ^
      ** %
    )

    COMMENT = '#'

    WS       = ' '
    NL       = "\n"
    T_DOT    = '.'
    T_LT     = '<'
    T_DLT    = '<<'
    T_AMP    = '&'
    T_ASN    = '='
    T_SPLAT  = '*'
    T_DSPLAT = '**'
    T_ASR    = '=>'
    T_PIPE   = '|'
    T_DCL    = '::'
    T_NEG    = '!'
    T_OR     = '||'
    T_AND    = '&&'
    T_COLON  = ':'

    M_PO  = '('
    M_PC  = ')'

    SNGL_QUOTE = "'"
    DBL_QUOTE  = '"'

    # Keywords
    K_DO       = 'do'
    K_DEF      = 'def'
    K_END      = 'end'
    K_BEGIN    = 'begin'
    K_CASE     = 'case'
    K_CLASS    = 'class'
    K_SELF     = 'self'
    K_ENSURE   = 'ensure'
    K_DEFINE   = 'define'
    K_MODULE   = 'module'
    K_RESCUE   = 'rescue'
    K_RETURN   = 'return'
    K_UNDEF    = 'undef'
    K_DEFINED  = 'defined?'
    K_PREEXE   = 'BEGIN'
    K_POSTEXE  = 'END'
    K_SUPER    = 'super'
    K_BREAK    = 'break'
    K_RETRY    = 'retry'
    K_REDO     = 'redo'
    K_NEXT     = 'next'
    K_FALSE    = 'false'
    K_TRUE     = 'true'
    K_IF       = 'if'
    K_AND      = 'and'
    K_ALIAS    = 'alias'
    K_ELSE     = 'else'
    K_ELSIF    = 'elsif'
    K_FOR      = 'for'
    K_NIL      = 'nil'
    K_NOT      = 'not'
    K_IN       = 'in'
    K_OR       = 'or'
    K_UNLESS   = 'unless'
    K_WHEN     = 'when'
    K_WHILE    = 'while'
    K_UNTIL    = 'until'
    K_YIELD    = 'yield'
    K_ENCODING = '__ENCODING__'
    K_EEND     = '__END__'
    K_FILE     = '__FILE__'
    K_THEN     = 'then'

    # Nodes that can be emitted in tokens that terminate their expression.
    #
    # These nodes dont require parentheses to be exactly reproduced in context of a more complex expression.
    #
    TERMINATED = symbol_set %w(
      int float self kwbegin const regexp args lvar
      ivar gvar cvar if case module class sclass super
      yield zsuper break next defined? str block while loop until
      def defs true false nil array hash sym return match_current_line
    )

    DEFAULT_DELIMITER = ', '.freeze

    CURLY_BRACKETS = IceNine.deep_freeze(%w({ }))

    KEYWORDS = constants.each_with_object([]) do |name, keywords|
      value = const_get(name).freeze
      if name.to_s.start_with?('K_')
        keywords << value.to_sym
      end
    end.to_set.freeze

  end # Constants
end # Unparser