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[perl #30123] foreach ("", "a".."zzzzzz") confuses range optimizer

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From:
Father Chrysostomos via RT
Date:
November 24, 2012 07:35
Subject:
[perl #30123] foreach ("", "a".."zzzzzz") confuses range optimizer
Message ID:
rt-3.6.HEAD-17500-1353771296-1.30123-15-0@perl.org
On Sat Nov 24 07:03:37 2012, alh wrote:
> On Sun, Sep 30, 2012 at 1:27 AM, Father Chrysostomos via RT <
> perlbug-followup@perl.org> wrote:
> 
> > On Sat Sep 29 19:08:16 2012, jkeenan wrote:
> > > On Fri Oct 15 09:32:02 2004, schwern wrote:
> > > > On Thu, 9 Sep 2004 22:47:35 +0100, Dave Mitchell <davem@iabyn.com>
> > wrote:
> > > > > I'm not sure how this can be construed as a bug. In the general
> > > > > case I'd expect 'a'..'zzzzzzz' to generate a large list, since P5
> > > doesn't
> > > > > have P6's lazy lists. It just so happens that C<for (X..Y)> is
> > > > > special-cased, but I don't see why that should lead to a general
> > > > > expcatation of lazy-listness?
> > > >
> > > > I have high expectations.
> > > >
> > > > Call it a feature request if it makes you feel better.  I
reported it
> > > > so its in the tracking system if someone wants to take a crack
at it.
> > > >
> > >
> > > Schwern,
> > >
> > > Is this still on your wishlist?
> >
> > It’s on *mine*.
> >
> 
> Is there anything blocking this from happening, or just the usual (time,
> effort, tuits)?

The usual, plus lack of inspiration.

> 
> Is there any other case besides for/foreach that 'a..z' should iterate on
> the fly rather than immediately generate a list in memory?

I hadn’t thought of that, but if it could iterate on the fly in more
places it would allow for more idiomatic code.

-- 

Father Chrysostomos


---
via perlbug:  queue: perl5 status: open
https://rt.perl.org:443/rt3/Ticket/Display.html?id=30123

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