RE: threads?
Although anecdotal, I've heard good things about Go's "channel" mechanism as a simple lightweight concurrency model and a good alternative to typical threading. Channels are first-class in the language and leverage simple "goroutine" semantics to invoke concurrency. --- Phil -Original Message- From: thoughtstr...@gmail.com [mailto:thoughtstr...@gmail.com] On Behalf Of Damian Conway Sent: October 12, 2010 10:23 AM To: perl6-language@perl.org Subject: Re: threads? Leon Timmermans wrote: > For the love of $DEITY, let's please not repeat ithreads! $AMEN! Backwards compatibility is not the major design criterion for Perl 6, so there's no need to recapitulate our own phylogeny here. The problem is: while most people can agree on what have proved to be unsatisfactory threading models, not many people can seem to agree on what would constititute a satisfactory threading model (or, possibly, models). What we really need is some anecdotal evidence from folks who are actually using threading in real-world situations (in *any* languages). What has worked in practice? What has worked well? What was painful? What was error-prone? And for which kinds of tasks? And we also need to stand back a little further and ask: is "threading" the right approach at all? Do threads work in *any* language? Are there better metaphors? Perhaps we need to think more Perlishly and reframe the entire question. Not: "What threading model do we need?", but: "What kinds of non-sequential programming tasks do we want to make easy...and how would we like to be able to specify those tasks?" As someone who doesn't (need to) use threading to solve the kinds of problems I work on, I'm well aware that I'm not the right person to help in this design work. We need those poor souls who already suffer under threads to share their tales of constant misery (and their occasional moments of triumph) so we can identify successful patterns of use and steal^Wborg^Wborrow the very best available solutions. Damian
RE: regex and
Back to your original advice...
> If you want to match an alphabetic string which does not include 'abc'
> anywhere, you can write this as
>
> ^ [ ]* $
I presume this only works here because is one character... if instead
of I used anything more complicated
(for example)
token name
{
<[A..Z]>*
}
And then tried to do ^ [ ]* $
This wouldn't work since there's a wildcard within name.
Once the & operator is in rakudo, though... I gather I /could/ do something
like the following
^ [ * & ] $
And this would in effect ensued that the sequence "abc" doesn't exist anywhere
across the match for
Is this correct?
RE: regex and
Great! That does it. Thanks. :)
I realized my error on the anchors after sending... but didn't think of the *
on the grouping.
On the & operator... are you saying that it would operate basically as
expected... allowing sets of rules and'ed rather than or's with the | ?
--- Phil
-Original Message-
From: Moritz Lenz [mailto:mor...@faui2k3.org]
Sent: August 10, 2010 2:09 PM
To: Beauchamp, Philippe (6009210)
Cc: perl6-language@perl.org
Subject: Re: regex and
Hi,
philippe.beauch...@bell.ca wrote:
> rule TOP
> {
> ^
> [
> & *
> &
> ]
> $
> }
The & syntax is specced, but it's not yet implemented in Rakudo.
But note that is a zero-width assertion, so your example regex
matches at the start of a string, if it does not begin with 'abc'.
Since you anchor it to the end of string too, it can only ever match the
empty string.
You can achieve the same with just ^$.
If you want to match an alphabetic string which does not include 'abc'
anywhere, you can write this as
^ [ ]* $
Cheers,
Moritz
regex and
Hi there...
New to the list and getting to understand perl6 after a bit of a hiatis from
the Perl world.
I'm working my way through the new grammar syntax trying to implement some
useful modules, and was wondering if there is a mechanism within the grammar
constructs to allow two rules to apply simultaneously in parallel (not
sequence).
In other words... I want to say that for a rule to pass it must pass two
contained rules completely.
Ie:
token abc
{
'abc'
}
rule TOP
{
^
[
& *
&
]
$
}
Such that the TOP rule would only match if a matching string consisted entirely
of alpha's AND did not contain the letter sequence "abc" anywhere in it.
(*note I know the & notation isn't legit ;)
