I'm talking about just in the same namespace, how
do we keep rules from messing with file-scoped
(or any-scoped, for that matter) lexicals or globals.
How do we get rule- or closure-scoped lexicals
that are put into $0?
How about something like the following rework of
the
Luke Palmer fretted:
This is terrible. Calling foo which calls bar mysteriously overwrites
$date? Why is $date changing? the programmer asks. He does an
exhaustive search through his code and finally says ohh, and has to
change all references to the inner $date to something like
I was thinking about regular expressions and hypotheticals again this
weekend, and something was bothering me quite a lot. How do rules create
hypotheticals?
Since a rule behaves like a closure, I can see how it could gain access
to existing lexicals, if it's declared inside of the same scope:
Going back to patterns, this gives us an added bonus. It not only
explains the behavior of hypotheticals, but also of subexpression
placeholders, which are created when the pattern returns:
$self but lexicals(0=$self, 1= $self.{1}, 2= $self.{2}, etc...)
That yields the side
I may be missing your point, but based on my somewhat
fuzzy understanding:
Oh. Duh. Why don't we have such a mechanism for matches?
m/ my $date := date /
is ambiguous to the eyes. But I think it's necessary to have a
lexical
scoping mechanism for matches
The above would at least have
On Mon, Sep 09, 2002 at 02:14:25PM -0500, Me wrote:
Hence the introduction of let:
m/ { let $date := date } /
which makes (a symbol table like entry for) $date available
somewhere via the match object.
Somewhere? where it appears in in the namespace of the caller.
Apparently there
On Mon, 9 Sep 2002, Andrew Wilson wrote:
On Mon, Sep 09, 2002 at 02:14:25PM -0500, Me wrote:
Hence the introduction of let:
m/ { let $date := date } /
which makes (a symbol table like entry for) $date available
somewhere via the match object.
Somewhere? where it appears in
On Mon, Sep 09, 2002 at 02:13:55PM -0600, Luke Palmer wrote:
Err.. I don't think so.
# Date.pm
grammar Date;
my $date;
rule date_rule { $date := something }
# uses_date.p6 (hmm.. I wonder what a nice extension would be...)
use Date;
my
On Mon, 2002-09-09 at 15:12, Luke Palmer wrote:
Going back to patterns, this gives us an added bonus. It not only
explains the behavior of hypotheticals, but also of subexpression
placeholders, which are created when the pattern returns:
[...]
I think this is a very clean and simple way
