CSE 321 Homework 15

1. Read the Lab4 assignment. Then carefully read the specs for the Program_Generate_Code abstract component in the 321 class notes. Explain where and how these specs rule out recursive BL programs.
2. Carefully read the the specification of the type and kernel operations for the BL_Tokenizing_Machine component in the 321 class notes.

   Implement the BL_Tokenizing_Machine_Get extension of BL_Tokenizing_Machine (see the 321 class notes). This component exports the two operations Get_Next_Token and Get_Next_Non_Separator_Token. Informally, Get_Next_Token returns in the arguments token_text and token_kind the next complete token read from the input stream str. Get_Next_Non_Separator_Token returns in the arguments token_text and token_kind the next complete non-white-space and non-comment token read from the input stream str. To read a single character from the input stream str, you can use the statement str.Read (ch), where ch is a Character object. Here is the concrete component BL_Tokenizing_Machine_Get_1 with the operations whose bodies you need to fill in.

---

//  /*----------------------------------------------------------------------*\
//  |   Concrete Template : BL_Tokenizing_Machine_Get_1
//  \*----------------------------------------------------------------------*/

#ifndef CT_BL_TOKENIZING_MACHINE_GET_1
#define CT_BL_TOKENIZING_MACHINE_GET_1 1

///------------------------------------------------------------------------
/// Global Context --------------------------------------------------------
///------------------------------------------------------------------------

#include "AI/BL_Tokenizing_Machine/Get.h"

///------------------------------------------------------------------------
/// Interface -------------------------------------------------------------
///------------------------------------------------------------------------

concrete_template <
        concrete_instance class BL_Tokenizing_Machine_Base
	/*!
	    implements
		abstract_instance BL_Tokenizing_Machine_Kernel
	!*/
    >
class BL_Tokenizing_Machine_Get_1 :
    implements
	concrete_instance BL_Tokenizing_Machine_Get,
    extends
	concrete_instance BL_Tokenizing_Machine_Base
{
public:

    procedure_body Get_Next_Token (
            alters   Character_IStream& str,
            produces Text& token_text,
            produces Integer& token_kind
        )
    {
        // Students fill this in
    }

    procedure_body Get_Next_Non_Separator_Token (
            alters   Character_IStream& str,
            produces Text& token_text,
            produces Integer& token_kind
        )
    {
        // Students fill this in
    }

};

#endif // CT_BL_TOKENIZING_MACHINE_GET_1