pragma

Hello all

Can everyone explain to me the PRAGMA instruction
(this instruction is for doing what ? how ? ...)

I don't find it on the autodesk documentation

Thanks



Luc Vallot
Chemin du Bassard
38121 Chonas l ' amballan
France


Tel: 04 74 58 95 68

 

You talkin bout 'progn'?

 

I believe pragma is termed a compiler directive.
It can be a help in writing programs in vlide
because user functions protected by pragma
turn blue. Vlide also warns when assignments
are made to such protected symbols.

When debugging code, however, it can be
tricky to reload pragma-protected symbols.
You need to unprotect the symbols
to be re-defined at the top of the file and
protect them at the bottom of the file.

To protect the symbols test and this
(pragma '((protect-assign test this)))

To unprotect the symbols test and this
(pragma '((unprotect-assign test this)))

There is no need to use pragma-xxx
statements IMO. I played around with them
for a while before deciding that they were
mostly a waste of time.

These functions are only necessary for someone
who is either bold enough or foolish enough
to redefine the built-in functions.

Regards,
Doug

 

(pragma) clauses are carried over from Vital LISP when it was
distributed by Basis Software and subsequently purchased by Autodesk and
labelled Visual LISP. They are no longer documented or supported but
still function.

Basically they are pre-compiler directives and can include a number of
compile modes and options. As suggested, protected symbols as well as
'link and 'not-link options which can improve the speed and efficiency
of large applications, 'drop and 'not-drop options to strip out function
names from resulting FAS/VLX files for increased security. Pragma's are
basically the coded version of the options available in the Project Make
file available from the Make Application menu in teh VLIDE.

Using these options can be tricky and must be done carefull, improper
placement or use can cause programs to run incorrectly or certain
elements not to function at all. For most purposes, the standard
compile mode can be used without these options.

Regards,

Jesse Danes