Builtin functions

The TSF language provides some functions to access directly to the lisp language provided by Foresys.

  $\blacktriangleright$ v.BUILTIN(n,p1,...,pn)

 
The   expression call the lisp function of name n with the arguments v,p1,...,pn. If the first argument v is a variable, then its is passed by reference.

  $\blacktriangleright$ v.BUILTIN_(n,p1,...,pn)

 
The BUILTIN_   attribute is a variant of BUILTIN in which the left hand side is not passed as an argument to the lisp function.

$\vartriangleright$ Example 55:The function Dialog:Util:AskUser (see section 8.15.1) can be implemented by the builtin #:xdialog:exec-ask.

  foo := foo.BUILTIN("\#:xdialog:exec-ask",
                     "The window title", 
                     "I am the message",
                     "Ok|Cancel",
                     3)

$\vartriangleright$ Example 56:Builtins are usefull when the TSF not provided a functionnality such as displaying the content of the undocumented value generated by the PATH attribute. The Lisp function print is used.

  foo := foo.BUILTIN_("print",$cstat.PATH($csel))

  $\vartriangleright$ Warning: Builtin functions is a dangerous feature. Each error can be fatal to Foresys.