Declarations in macro definitions

* Declarations in macro definitions
@ 2002-03-17 12:34 Gerd Moellmann
  2002-03-18  9:05 ` Richard Stallman
  0 siblings, 1 reply; 8+ messages in thread
From: Gerd Moellmann @ 2002-03-17 12:34 UTC (permalink / raw)

Reading some Lisp code today which contained declarations for ZWEI
inspired me to the following simple hack.  It let's one declare
indentation and Edebug specs in a defmacro, like

        (defmacro foo ()
           (declare (indent INDENT) (debug DEBUG))
           ...)

where INDENT is used for `lisp-indent-function', and DEBUG is used for
`edebug-form-spec'.

What do people think?

*** eval.c	2002/03/17 11:10:24	1.182
--- eval.c	2002/03/17 12:17:12
***************
*** 91,96 ****
--- 91,97 ----
  Lisp_Object Qinhibit_quit, Vinhibit_quit, Vquit_flag;
  Lisp_Object Qand_rest, Qand_optional;
  Lisp_Object Qdebug_on_error;
+ Lisp_Object Qdeclare;

  /* This holds either the symbol `run-hooks' or nil.
     It is nil at an early stage of startup, and when Emacs
***************
*** 189,194 ****
--- 190,200 ----

  int handling_signal;

+ /* Function to process declarations in defmacro forms.  */
+ 
+ Lisp_Object Vmacro_declaration_function;
+ 
+ 
  static Lisp_Object funcall_lambda P_ ((Lisp_Object, int, Lisp_Object*));

  void
***************
*** 651,659 ****
  {
    register Lisp_Object fn_name;
    register Lisp_Object defn;

    fn_name = Fcar (args);
!   defn = Fcons (Qmacro, Fcons (Qlambda, Fcdr (args)));
    if (!NILP (Vpurify_flag))
      defn = Fpurecopy (defn);
    Ffset (fn_name, defn);
--- 657,695 ----
  {
    register Lisp_Object fn_name;
    register Lisp_Object defn;
+   Lisp_Object lambda_list, doc, tail;

    fn_name = Fcar (args);
!   lambda_list = Fcar (Fcdr (args));
!   tail = Fcdr (Fcdr (args));
! 
!   doc = Qnil;
!   if (STRINGP (Fcar (tail)))
!     {
!       doc = Fcar (tail);
!       tail = Fcdr (tail);
!     }
! 
!   while (CONSP (Fcar (tail))
! 	 && EQ (Fcar (Fcar (tail)), Qdeclare))
!     {
!       if (!NILP (Vmacro_declaration_function))
! 	{
! 	  struct gcpro gcpro1;
! 	  GCPRO1 (args);
! 	  call2 (Vmacro_declaration_function, fn_name, Fcar (tail));
! 	  UNGCPRO;
! 	}
!       
!       tail = Fcdr (tail);
!     }
! 
!   if (NILP (doc))
!     tail = Fcons (lambda_list, tail);
!   else
!     tail = Fcons (lambda_list, Fcons (doc, tail));
!   defn = Fcons (Qmacro, Fcons (Qlambda, tail));
!   
    if (!NILP (Vpurify_flag))
      defn = Fpurecopy (defn);
    Ffset (fn_name, defn);
***************
*** 3229,3234 ****
--- 3265,3273 ----
    Qmacro = intern ("macro");
    staticpro (&Qmacro);

+   Qdeclare = intern ("declare");
+   staticpro (&Qdeclare);
+   
    /* Note that the process handling also uses Qexit, but we don't want
       to staticpro it twice, so we just do it here.  */
    Qexit = intern ("exit");
***************
*** 3313,3318 ****
--- 3352,3365 ----
  Note that `debug-on-error', `debug-on-quit' and friends
  still determine whether to handle the particular condition.  */);
    Vdebug_on_signal = Qnil;
+ 
+   DEFVAR_LISP ("macro-declaration-function", &Vmacro_declaration_function,
+ 	       doc: /* Function to process declarations in a macro definition.
+ The function will be called with two args MACRO and DECL.
+ MACRO is the name of the macro being defined.
+ DECL is a list '(declare ...)' containing the declarations.
+ The value the function returns is not used.  */);
+   Vmacro_declaration_function = Qnil;

    Vrun_hooks = intern ("run-hooks");
    staticpro (&Vrun_hooks);

*** subr.el	2002/03/17 11:58:18	1.291
--- subr.el	2002/03/17 12:14:14
***************
*** 32,37 ****
--- 32,55 ----
  (defun custom-declare-variable-early (&rest arguments)
    (setq custom-declare-variable-list
  	(cons arguments custom-declare-variable-list)))
+ 
+ \f
+ (defun macro-declaration-function (macro decl)
+   "Process a declaration found in a macro definition.
+ This is set as the value of the variable `macro-declaration-function'.
+ MACRO is the name of the macro being defined.
+ DECL is a list `(declare ...)' containing the declarations.
+ The return value of this function is not used."
+   (dolist (d (cdr decl))
+     (cond ((and (consp d) (eq (car d) 'indent))
+ 	   (put macro 'lisp-indent-function (cadr d)))
+ 	  ((and (consp d) (eq (car d) 'debug))
+ 	   (put macro 'edebug-form-spec (cadr d)))
+ 	  (t
+ 	   (message "Unknown declaration %s" d)))))
+ 
+ (setq macro-declaration-function 'macro-declaration-function)
+ 
  \f
  ;;;; Lisp language features.

_______________________________________________
Emacs-devel mailing list
Emacs-devel@gnu.org
http://mail.gnu.org/mailman/listinfo/emacs-devel

^ permalink raw reply	[flat|nested] 8+ messages in thread