On Fri, Apr 11, 2008 at 5:32 AM, Patrick R. Michaud <[EMAIL PROTECTED]> wrote:
> With some recent PCT-related changes I think we may want to
> update the tutorials a bit.
>
> 1. Remove the custom "List" class.
>
> ResizablePMCArray now has built-in shift/unshift/push/pop
> methods, so we can use it directly from NQP and don't need
> to create a custom List class to be able to invoke these
> operations.
>
> 2. Remove :scope attribute from PAST::Var nodes.
>
> My intent has been that most PAST::Var nodes for simple variables
> would not require individual scope attributes; with the changes
> I checked into Parrot tonight this should be easier. In Squaak's
> case this means that the C<identifier> action method should now
> read:
>
> method identifier($/) {
> make PAST::Var.new( :name($name),
> :viviself('Undef'),
> :node($/) );
> }
>
> In particular, note that there's no longer a need to
> explicitly search outer blocks for the scope -- PCT
> will handle this automatically.
>
> To indicate that all undeclared variables should default
> to 'package' scope, we use the C<symbol_defaults> method on
> the top-level block. For Squaak, we add the following to its
> TOP action method:
>
> $?BLOCK.symbol_defaults(:scope('package'));
>
> This says that 'package' scope is to be used for any PAST::Var
> node that doesn't have its own :scope and that doesn't have a
> scope provided by an outer block's symbol hash.
>
>
> 3. (Bonus problem) Eliminate @?BLOCK
>
> Since PAST::Var nodes no longer need to search outer blocks
> (PCT will handle that), we no longer need to maintain a @?BLOCK
> array. So, for bonus points, eliminate @?BLOCK from the Squaak
> methods.
>
I don't really see immediately that @?BLOCK can be removed...
blocks open and close, but $?BLOCk should always point to the current
block, right?
So, in order to restore $?BLOCK, we need to store the old one
somewhere, and this must be done in a LIFO order (to allow for
multiple nested blocks).
Maybe I'm missing something. Could you explain this a bit?
thanks!
kjs
>
> If I can help explain or demonstrate any of the above, let me know.
> Thanks!
>
> Pm
>
