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

    UNARY_OPERATORS = %w(
      ! ~ -@ +@
    ).map(&:to_sym).to_set

    BINARY_OPERATORS = %w(
      + - * / & | && || << >> ==
      === != <= < <=> > >= =~ !~ ^
      ** %
    ).map(&:to_sym).to_set

    COMMENT = '#'.freeze

    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  = ')'

    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'

    TERMINATED = [
      :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
    ].to_set

    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