[Petal] bug: documentation uses unsupported (but TAL spec) modifier

[Jonathan]

I noticed this today in the petal documentation:

=======
omit-tag

Abstract

   <tag tal:omit-tag="EXPRESSION">Some contents</tag>
Example

   <b tal:omit-tag="not:bold">I may not be bold.</b>
If not:bold is evaluated as TRUE, then the <b> tag will be omited. If  
not:bold is evaluated as FALSE, then the <b> tag will stay in place.

Why?

omit-tag statements can be used to leave the contents of a tag in  
place while omitting the surrounding start and end tags if the  
expression which is evaluated is TRUE.

TIP:

If you want to ALWAYS remove a tag, you can use omit-tag="string:1"

=======

i've discussed this before, but "not:" is a TAL modifier that isn't  
in petal

i just wanted to bring this up again, as following the docs in this  
case will cause an error

i suggest either:
	* patching petal to use not: which is in the TAL spec (patch below)
	* including the Petal Modifier on the TAL doc, so that will work and  
others in the future will see it
	* changing the docs from not to false

in that order of preference

Petal Modifier method:

=====
use Petal ();
$Petal::Hash::MODIFIERS->{'not:'} = sub { return ( $_[0]->fetch($_ 
[1]) ? 0 : 1 ); };
=====

Patch

=====
diff -Naur Petal-2.18-dist/lib/Petal/Hash.pm Petal-2.18-patched/lib/ 
Petal/Hash.pm
--- Petal-2.18-dist/lib/Petal/Hash.pm   2005-03-16 10:23:36.000000000  
-0500
+++ Petal-2.18-patched/lib/Petal/Hash.pm        2006-01-20  
16:08:20.000000000 -0500
@@ -71,6 +71,14 @@
};
+# not modifier
+$MODIFIERS->{'not:'} = sub {
+    my $hash = shift;
+    my $variable = join ' ', @_;
+    return not $hash->fetch ("true:$variable");
+};
+
+
# encode: modifier (deprecated stuff)
$MODIFIERS->{'encode:'} = sub {
      warn "Petal modifier encode: is deprecated";
=====

Sorry, but I don't know the correct way to generate a diff for patching.

it's just adding this
====
# not modifier
$MODIFIERS->{'not:'} = sub {
     my $hash = shift;
     my $variable = join ' ', @_;
     return not $hash->fetch ("true:$variable");
};
=====

to lib/Petal/Hash.pm - its an exact copy of the false function, just  
s/false/not/g , and right below it.  there's probably a better way to  
consolidate not: and false: into 1 modifier, but that works.