module Risc
  module Builtin
    module Word
      module ClassMethods
        include CompileHelper

        # wrapper for the syscall
        # io/file currently hardcoded to stdout
        # set up registers for syscall, ie
        # - pointer in r1
        # - length in r2
        # - emit_syscall (which does the return of an integer, see there)
        def putstring( context)
          compiler = compiler_for(:Word , :putstring ,{})
          builder = compiler.builder(compiler.source)
          builder.prepare_int_return # makes integer_tmp variable as return
          builder.build do
            word! << message[:receiver]
            integer! << word[Parfait::Word.get_length_index]
          end
          Risc::Builtin::Object.emit_syscall( builder , :putstring )
          compiler.add_mom( Mom::ReturnSequence.new)
          compiler
        end

        # self[index] basically. Index is the first arg > 0
        # return a word sized new int, in return_value
        #
        # Note: no index (or type) checking. Method should be internal and check before.
        #       Which means the returned integer could be passed in, instead of allocated.
        def get_internal_byte( context)
          compiler = compiler_for(:Word , :get_internal_byte , {at: :Integer})
          builder = compiler.builder(compiler.source)
          integer_tmp = builder.allocate_int
          builder.build do
            object! << message[:receiver]
            integer! << message[:arguments]
            integer << integer[Parfait::NamedList.type_length + 0] #"at" is at index 0
            integer.reduce_int
            object <= object[integer]
            integer_tmp[Parfait::Integer.integer_index] << object
            message[:return_value] << integer_tmp
          end
          compiler.add_mom( Mom::ReturnSequence.new)
          return compiler
        end

        # self[index] = val basically. Index is the first arg ( >0 , unchecked),
        # value the second, which is also returned
        def set_internal_byte( context )
          compiler = compiler_for(:Word, :set_internal_byte , {at: :Integer , value: :Integer} )
          compiler.builder(compiler.source).build do
            word! << message[:receiver]
            integer! << message[:arguments]
            integer_reg! << integer[Parfait::NamedList.type_length + 1] #"value" is at index 1
            message[:return_value] << integer_reg
            integer << integer[Parfait::NamedList.type_length + 0] #"at" is at index 0
            integer.reduce_int
            integer_reg.reduce_int
            word[integer] <= integer_reg
          end
          compiler.add_mom( Mom::ReturnSequence.new)
          return compiler
        end

      end
      extend ClassMethods
    end
  end
end