Allows source location to work when a form is copied by a macro.
replacement-source-form original-form new-form => new-form-value
A Lisp form.
A Lisp form.
A Lisp object.
A call to
replacement-source-form can be used to allow the debugger and stepper to identify that original-form has been replaced by new-form in a macro expansion. Forms in a macro expansion that are
eq to forms in the arguments to the macro will be identified automatically, but some macros (such as
) need to generate new forms that are equivalent to the original forms and wrapping them with
replacement-source-form allows them to be identified too.
original-form should be a form that occurred in the arguments to the macro and does not otherwise occur in the expansion of the macro. new-form should be a form that was created by the macro.
The value of new-form, new-form-value, is returned when the
replacement-source-form form is evaluated.
dspec:replacement-source-form, the calls to
pprint would be unknown to the debugger and stepper because the forms do not occur in the original source code:
(defmacro pprint-for-print (&body forms)
,@(loop for form in forms
(if (and (consp form)
(eq (car form) 'print))
(pprint ,@(cdr form)))
LispWorks User Guide and Reference Manual - 20 Sep 2017