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Enhancing Migrated HP Business BASIC/V Applications
To enhance your migrated HP Business BASIC/V programs, use the new
features listed below. New features are HP Business BASIC/XL features
that are not offered in HP Business BASIC/V. For more information about
any of the features listed below, refer to the HP Business BASIC/XL
Reference Manual.
* New Options in the EXTERNAL Statement.
HP Pascal has a new procedure option, EXTENSIBLE, that specifies the
minimum number of parameters to be passed to a procedure. Required
formal parameters are called nonextension parameters. Optional
formal parameters are called extension parameters. HP Business
BASIC/XL interfaces with this option through the EXTENSIBLE clause of
the EXTERNAL Pascal statement. Some intrinsics include this as a
specified procedure option contained in the intrinsic file. In HP
Business BASIC/XL, you specify the required number of parameters as a
numeric literal. The rest of the parameters are optional. A hidden
parameter that indicates the number of parameters passed is passes to
the external routine.
Missing actual parameters are supplied when the intrinsic file
specifies default values.
You can specify the EXTENSIBLE clause in the EXTERNAL Pascal
statement as shown below:
EXTERNAL PASCAL
[EXTENSIBLE=[num_literal]][function_return_type]external_name
[ALIAS alias_name][parameter_list]
* Calls to HP C/XL Are Supported.
HP C/XL is a native mode language on MPE XL. HP Business BASIC/XL
supports calls to HP C/XL through the EXTERNAL statement. Every HP
Business BASIC/XL data type is a valid parameter for HP C/XL external
routines.
EXTERNAL HPC
[function_return_type]external_name[ALIAS alias_name][parameter_list]
For complete information about the EXTERNAL statement, refer to the
HP Business BASIC/XL Reference Manual.
* IN DATA SET REALV.
IN DATASET dset USE REALV pack_item_list
TurboIMAGE databases are STORE/RESTORE compatible; real numbers in
database files are stored in MPE V real format. The default real
data type in a native mode program is in IEEE real format. Specify
"REALV" in the IN DATASET statement if you use real data types as a
search condition or as a key in sorting. See chapter 5, "Migrating
TurboIMAGE/V Databases," for detailed information about database
migration with real data type.
* PACKFMT REALV.
PACKFMT REALV pack_item_list
Use PACK and UNPACK statements for writing values to and reading
values from strings. Specify the variables being moved in the
PACKFMT list. The default real data type in native mode programs is
in IEEE floating-point real format; you must specify "REALV" in the
PACKFMT statement if you want to use MPE V real data format. For
example, if an HP Business BASIC/XL data file is being shared among
native mode and compatibility mode programs and real variables are
being packed and unpacked, specify "REALV" in the PACKFMT list to
preserve data integrity. IEEE real numbers are changed to MPE V real
numbers before variables are written to the string. MPE V real
numbers are changed to IEEE real numbers before the value in the
string is assigned to the appropriate variable.
See chapter 5, "Migrating TurboIMAGE/V Databases," for more
information about database migration with REAL data type.
* GLOBAL COPTION RLFILE.
GLOBAL COPTION RLFILE compiles each main and each procedure or
function into a separate object code file. Compiler output is a
relocatable library (NMRL) file instead of an object (NMOBJ) file.
More than one program subunit can be compiled into a Relocatable
Library (RL). Use Relocatable Libraries for storing subprograms that
contain frequently used common routines. The library routine in the
relocatable object module becomes part of the program file when the
link editor merges the relocatable object containing the referenced
code into the program file. Once the executable program file is
created, the program is insulated from changes made to library
routines. Relink the program using the modified library when you
want to incorporate library changes into a program. Refer to the HP
Link Editor/XL Reference Manual for more information about using RL
files.
* GLOBAL COPTION RLINIT.
The GLOBAL COPTION RLINIT compiler option is valid only if the RLFILE
option is on. Use is when you are compiling into an existing NMRL
file that you want to initialize before compiling.
* COPTION LOCALITY = quoted-str-lit.
The COPTION LOCALITY compiler option names the locality set that
subprograms are placed in. Using locality names improves program
performance when calling a routine in the same locality set requires
fewer page faults than calling a routine in a different locality set.
COPTION LOCALITY = quoted-str-lit is only valid if the RL file option
is on. Refer to the HP Link Editor/XL Reference Manual for more
information.
* COMPLK.
Use the COMPLK command to compile and link programs in the
interpreter. This command is similar to COMPPREP on MPE V.
* GLOBAL COPTION OPTIMIZE = {0|1} This option controls the level of
program optimization. Compile time increases as the level of
optimization increases, but execution time and code size decrease.
Level 1 optimization, the default, rearranges instructions within an
individual statement and eliminates unnecessary or redundant
instructions. The result is an object code file that is both smaller
and faster than level 0. Level 0 optimization is useful for
debugging with DEBUG/XL because the line numbers of the program are
displayed in the program window.