[Templates] Proposed changes to list.hash and hash.list vmethods

[Andy Wardley]

I just got bitten (again) by a limitation in Template::Stash.  Stephen
Howard provided a patch to fix it and I added it, but left it commented
out pending comments from anyone (and also pending the tuits to dive
into the XS Stash to make the same fix).

http://template-toolkit.org/pipermail/templates/2003-December/005417.html

The essence of the problem is this: if you have an object (list or hash)
which doesn't implement the method that you call, then it should fall
back on hash/list vmethods, or accessing the numerical item you asked
for in a list.

   [% hashobject.keys  %]    # should call hash vmethod, but doesn't
   [% listobject.first %]    # ditto list vmethod
   [% listobject.3     %]    # should return $listobject->[3]

Needless to say, the problem is that it doesn't, but with Stephen's
patch, it does (in the Perl Template::Stash at least).

Well we don't seem to have had any comments since then, and with fresh 
bite marks to show for it, I'm going ahead and activating it unless I 
hear any blood-curdling screams to the contrary.

I'll also have a look at updating the XS Stash to do the same thing
so you may be hearing a few blood-curdling screams from me :-)

While I'm there, I'm also planning to "fix" the hash.list and list.hash 
methods to Do The Right Thing.

For some totally half-baked reason that now I can fathom not, I made 
the hash.list method return a stupidly complex list of hash references:

  { pi => 3.14 } => [ { key ='pi', value='3.14' } ]

and the list.hash method return an equally useless hash:

  [ 3.14, 2.718 ] => { 0 => 3.14, 1 => 2.718 }

Having just activated Stephen's patch, these vmethods kicked in and 
made a handful of tests failed because they were expecting some kind 
of sensible values returned and instead got this crack-fuelled nonsense.

So I'm proposing that I fix them too and make them do what they should
always have done - a straight conversion between list and hash

  hash.list => [ %$hash ]
  list.hash => { @$list }

I realise that it might break code that relies on the old behaviour,
but I think it's for the best in the long run.

Any objections?

A