Check if a symbol is bound to a macro

Check if a symbol is bound to a macro

[Nordlöw]

Is there a way to query if a symbol is bound to a macro?

list-fns.el written by Noah Friedman provides the function

(defun macrop (x)
  "Return `t' if X is a macro, `nil' otherwise.
X may be a raw or byte-compiled macro.  No attempt is made to
determine if
the macro is actually well-formed (i.e. syntactically valid)."
  (cond ((not (consp x))
         nil)
        ((eq (car x) 'macro)
         (functionp (cdr x)))))

but it doesn't work for me.
  (macrop 'case)
returns nil.

Thanks,
Nordlöw

Re: Check if a symbol is bound to a macro

[Barry Margolin]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 1037 bytes --]

In article 
<b240c2eb-6d28-410a-aa2d-4ea28568585b@a32g2000yqm.googlegroups.com>,
 Nordlöw <per.nordlow@gmail.com> wrote:

> Is there a way to query if a symbol is bound to a macro?
> 
> list-fns.el written by Noah Friedman provides the function
> 
> (defun macrop (x)
>   "Return `t' if X is a macro, `nil' otherwise.
> X may be a raw or byte-compiled macro.  No attempt is made to
> determine if
> the macro is actually well-formed (i.e. syntactically valid)."
>   (cond ((not (consp x))
>          nil)
>         ((eq (car x) 'macro)
>          (functionp (cdr x)))))
> 
> but it doesn't work for me.
>   (macrop 'case)
> returns nil.
> 
> Thanks,
> Nordlöw

macrop expects the function, not the function name, as its argument.  So 
you need to do:

(defun named-macrop (symbol)
  (and (fboundp symbol)
       (macrop (symbol-function symbol))))

-- 
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***

Re: Check if a symbol is bound to a macro

[Nordlöw]

On Dec 8, 9:52 pm, Barry Margolin <bar...@alum.mit.edu> wrote:
> In article
> <b240c2eb-6d28-410a-aa2d-4ea285685...@a32g2000yqm.googlegroups.com>,
>
>
>
>
>
>  Nordlöw <per.nord...@gmail.com> wrote:
> > Is there a way to query if a symbol is bound to a macro?
>
> > list-fns.el written by Noah Friedman provides the function
>
> > (defun macrop (x)
> >   "Return `t' if X is a macro, `nil' otherwise.
> > X may be a raw or byte-compiled macro.  No attempt is made to
> > determine if
> > the macro is actually well-formed (i.e. syntactically valid)."
> >   (cond ((not (consp x))
> >          nil)
> >         ((eq (car x) 'macro)
> >          (functionp (cdr x)))))
>
> > but it doesn't work for me.
> >   (macrop 'case)
> > returns nil.
>
> > Thanks,
> > Nordlöw
>
> macrop expects the function, not the function name, as its argument.  So
> you need to do:
>
> (defun named-macrop (symbol)
>   (and (fboundp symbol)
>        (macrop (symbol-function symbol))))
>
> --
> Barry Margolin, bar...@alum.mit.edu
> Arlington, MA
> *** PLEASE post questions in newsgroups, not directly to me ***
> *** PLEASE don't copy me on replies, I'll read them in the group ***

Thanks!
/Per Nordlöw