On Tue, 21 Oct 2008, Timothy S. Nelson wrote:
On Tue, 21 Oct 2008, David Green wrote:
On 2008-Oct-2, at 6:15 pm, Timothy S. Nelson wrote:
The guys on IRC convinced me that the way to go might be something like
a grammar, but that does trees and tree transformations instead of a
text input stream. See the IRC log for details :).
[...]
<TimToady> note to treematching folks: it is envisaged that signatures in
a
rule will match nodes in a tree
There does seem to be a clever idea waiting to happen here, although I
expect signatures will be somewhat simpler since they are intended for a
more specific purpose.
One thing I would like signatures to be able to do, though, is assign
parameters by type. Much like a rule can look for identifiable objects
like a <block> or <ident>, it would be very useful to look for parameters
by their type or class rather than by name (or position).
For example, if I ask you to hand me a hammer and a nail, I don't need you
to hand them to me in a specific order, or with labels attached like a Dick
Tracy comic, in order to know which is which. That's obvious, because,
well, one is a hammer and one is a nail. If I'm writing OO-code, then Perl
also knows what's a Tool::Hammer and what's a Fastener::Nail -- if I know
that my $tool is a hammer, and Perl knows, then I shouldn't have to spell
it out.
XPath does this by default, and XPath is what I'd want to model any
tree-based stuff on, because it has a pretty comprehensive tree model. But
having said that, I'm not sure that I want to do it by default. It'd
certainly be an option, though.
Having read TSa's post, I'm no longer sure that what I said about
XPath relates to what David wants.
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| Name: Tim Nelson | Because the Creator is, |
| E-mail: [EMAIL PROTECTED] | I am |
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