# frozen_string_literal: true

module Rpl
  module Lang
    module Core
      module_function

      # no operation
      def nop( stack, dictionary )
        [stack, dictionary]
      end

      # show version
      def version( stack, dictionary )
        stack += Rpl::Interpreter.parse( Rpl::Lang.version.to_s )

        [stack, dictionary]
      end

      # show complete identification string
      def uname( stack, dictionary )
        stack += Rpl::Interpreter.parse( "\"Rpl Interpreter version #{Rpl::Lang.version}\"" )

        [stack, dictionary]
      end

      def help( stack, dictionary )
        stack, args = Rpl::Lang.stack_extract( stack, [%i[name]] )

        word = dictionary.words[ args[0][:value] ]

        stack << { type: :string,
                   value: "#{args[0][:value]}: #{word.nil? ? 'not a core word' : word[:help]}" }

        [stack, dictionary]
      end
    end
  end
end