HP OpenVMS Systems

Calling Standard and Argument Passing?

» close window

The Question is:

 
Using Compaq Basic how can I pass an array defined as part of a record statment
 to an external subroutine. When I try, I get argument mismatch errors, or
 other similar errors.
 
The goal is to create a array sort in which an
array name is passed as a parameter.
 
Example:
 
        RECORD X
                VARIANT
                        CASE
                                STRING E.DATE$ = 8%
                                STRING N.V$ = 1%
                                STRING P.V$ = 1%
                        CASE
                                STRING RECORD.$ = 10%
                END VARIANT
        END RECORD
 
       DECLARE X TEST(20%)
 
       CALL QSRT( TEST(), MAX%, 1%, 9%, STATUS%)
       .
       .
       .
 
 
       SUB QSRT(STRING ARRAY$(), LONG ITEM.COUNT%, LONG KEY.START%, &
                        LONG KEY.LEN%, LONG RET.VALUE%)
 
        OPTION TYPE = EXPLICIT
        ON ERROR GOTO ERROR_TRAP
        .
        .
        .
 
 
Thanks,
 
Dan Harmon
 
 

The Answer is :

 
  You will want to become more familiar with the calling standard and
  with the debugger, and you will also need to become familiar with
  what argument-passing directives are available in BASIC.  (You might
  end up creating a set of jacket routines.)
 
  As a starting point, get the call to the QSRT subroutine working
  using an existing example or other resources.  Then use the debugger
  to examine the parameter passing and particularly descriptor(s) used.
  In conjunction with the calling standard, determine how to create and
  pass the necessary descriptors.
 

  

     

     
answer written or last revised on ( 15-DEC-2000 )
     
» close window