Re: FYI: On the way to -w

[Akim Demaille]

Tom, I'd like to know what you'd prefer: fixing the uses of $2 etc.,
or the definition of the groups in the regexps?  For instance, I have
this:

Index: automake.in
===================================================================
RCS file: /cvs/automake/automake/automake.in,v
retrieving revision 1.970
diff -u -u -r1.970 automake.in
--- automake.in 2001/03/05 19:29:16 1.970
+++ automake.in 2001/03/05 19:37:25
@@ -1,4 +1,4 @@
address@hidden@
address@hidden@ -w
 # -*- perl -*-
 # @configure_input@
 
@@ -6726,8 +6726,8 @@
          # line).
          # I'm quite shoked!  It seems that (\\\n|[^\n]) is not the
          # same as `([^\n]|\\\n)!!!  Don't swap it, it breaks.
-         my ($relationship, $actions) =
-           /^((?:\\\n|[^\n])*)(?:\n(\t.*))?$/som;
+         /^((?:\\\n|[^\n])*)(?:\n(\t.*))?$/som;
+         my ($relationship, $actions) = ($1, $2 || '');
 
          # Separate targets from dependencies: the first colon.
          $relationship =~ /^([^:]+\S+) *: *(.*)$/som;
@@ -6843,8 +6843,9 @@
     {
        if ($varname =~ /^(nobase_)?(dist_|nodist_)?(.*)_$primary$/)
        {
-           if (($2 ne '' && ! $can_dist)
-               || (! defined $valid{$3} && ! &variable_defined ($3 . 'dir')))
+           my ($base, $dist, $X) = ($1 || '', $2 || '', $3 || '');
+           if (($dist ne '' && ! $can_dist)
+               || (! defined $valid{$X} && ! &variable_defined ("${X}dir")))
            {
                # Note that a configure variable is always legitimate.
                # It is natural to name such variables after the
@@ -6857,7 +6858,7 @@
            else
            {
                # Ensure all extended prefixes are actually used.
-               $valid{$1 . $2 . $3} = 1;
+               $valid{"$base$dist$X"} = 1;
            }
        }
     }

Changing the regexp would make them much more complex.