Subject: 23.1; etags of perl "use constant"
From: Kevin Ryde <[email-masked]>
To: [email-masked]
Date: Fri, 27 Nov 2009 11:17:20 +1100

It'd be good if etags recognised perl constants like

    use constant FOO => 123;

which defines a subroutine called FOO, basically the same as if you
wrote

    sub FOO () { return 123 }

"constant::defer" in the diff below is one of my things.  Is it too
cheeky to slip that in?  It's on cpan, but probably used only by me as
yet :-).

2009-11-27  Kevin Ryde  <[email-masked]>

	* etags.c (Perl_functions): Tag "use constant" subs too.

	* maintaining.texi (Tag Syntax): Add Perl "use constant".

Index: lib-src/etags.c
===================================================================
RCS file: /sources/emacs/emacs/lib-src/etags.c,v
retrieving revision 3.93
diff -u -r3.93 etags.c
--- lib-src/etags.c	23 Nov 2009 09:51:06 -0000	3.93
+++ lib-src/etags.c	27 Nov 2009 00:05:52 -0000
@@ -4388,6 +4388,7 @@
 /*
  * Perl support
  * Perl sub names: /^sub[ \t\n]+[^ \t\n{]+/
+ *                 /^use constant[ \t\n]+[^ \t\n{=,;]+/
  * Perl variable names: /^(my|local).../
  * Original code by Bart Robinson <[email-masked]> (1995)
  * Additions by Michael Ernst <[email-masked]> (1997)
@@ -4411,9 +4412,9 @@
 	}
       else if (LOOKING_AT (cp, "sub"))
 	{
-	  char *pos;
-	  char *sp = cp;
-
+	  char *pos, *sp;
+	subr:
+	  sp = cp;
 	  while (!notinname (*cp))
 	    cp++;
 	  if (cp == sp)
@@ -4436,6 +4437,21 @@
 			lb.buffer, cp - lb.buffer + 1, lineno, linecharno);
 	      free (name);
 	    }
+	}
+      else if (LOOKING_AT (cp, "use constant")
+	       || LOOKING_AT (cp, "use constant::defer"))
+	{
+	  /* For hash style multi-constant like
+	   *     use constant { FOO => 123,
+	   *                    BAR => 456 };
+	   * only the first FOO is picked up.  Parsing across the value
+	   * expressions would be difficult in general, due to possible nested
+	   * hashes, here-documents, etc.  Maybe simple values could be
+	   * handled.
+	   */
+	  if (*cp == '{')
+	    cp = skip_spaces (cp+1);
+	  goto subr;
  	}
        else if (globals)	/* only if we are tagging global vars */
  	{
Index: doc/emacs/maintaining.texi
===================================================================
RCS file: /sources/emacs/emacs/doc/emacs/maintaining.texi,v
retrieving revision 1.22
diff -u -r1.22 maintaining.texi
--- doc/emacs/maintaining.texi	11 Jul 2009 02:49:07 -0000	1.22
+++ doc/emacs/maintaining.texi	27 Nov 2009 00:06:02 -0000
@@ -1681,7 +1681,8 @@
 
 @item
 In Perl code, the tags are the packages, subroutines and variables
-defined by the @code{package}, @code{sub}, @code{my} and @code{local}
+defined by the @code{package}, @code{sub}, @code{use constant},
+@code{my} and @code{local}
 keywords.  Use @samp{--globals} if you want to tag global variables.
 Tags for subroutines are named @samp{@var{package}::@var{sub}}.  The
 name for subroutines defined in the default package is

In GNU Emacs 23.1.1 (i486-pc-linux-gnu, GTK+ Version 2.16.5)
 of 2009-09-14 on raven, modified by Debian
configured using `configure  '--build=i486-linux-gnu' '--host=i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' '--localstatedir=/var/lib' '--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes' '--enable-locallisppath=/etc/emacs23:/etc/emacs:/usr/local/share/emacs/23.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.1/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/23.1/leim' '--with-x=yes' '--with-x-toolkit=gtk' '--with-toolkit-scroll-bars' 'build_alias=i486-linux-gnu' 'host_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -g -O2' 'LDFLAGS=-g' 'CPPFLAGS=''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_AU
  value of $XMODIFIERS: nil
  locale-coding-system: iso-latin-1-unix
  default-enable-multibyte-characters: t