Re^2: One liner to Check and undef hash elements (shortcircuiting)

Doh, I knew there was a single step approach for Nr.2.. it just wouldn't occur to me last night.

I'm not sure I like your approach to the first one though - using a subref to get around the lack of control in naked blocks seems to hackish. I'm not really happy with my own alternative, either:

my $hash_has_non_undef = do {
    local $_;
    my $found = 0;

    defined && ($found++, last)
        while (undef, $_) = each %hash;

    $found;
};
[download]

But without Perl 6 junctions there's not much that can be done about it if you need shortcircuiting..

Makeshifts last the longest.

Comment on Re^2: One liner to Check and undef hash elements (shortcircuiting) Download Code

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•Re: Re^2: One liner to Check and undef hash elements (shortcircuiting) by merlyn (Sage) on Apr 16, 2003 at 11:46 UTC
Well, the non-sub way could look like this: `my $hash_has_non_undef = do { my $found; until($found or not (undef, m +y $v) = each %hash) { $found = defined $v } $found };` [download] I mean, that's the way we had to do it in Pascal. Stupid boolean flag variables all over the place because they wouldn't let us exit blocks. {grin} Doh! As I'm staring at this, I realize the `$v` can do double duty. `my $hash_has_non_undef = do { my $v; until($v or not (undef, $v) = eac +h %hash) { $v = defined $v } $v };` [download] But that's optimized for Golf, not for maintenance. Ick. -- Randal L. Schwartz, Perl hacker Be sure to read my standard disclaimer if this is a reply.	[reply] [d/l] [select]
Re^4: One liner to Check and undef hash elements (shortcircuiting) by Aristotle (Chancellor) on Apr 16, 2003 at 11:53 UTC
Yeah, I know.. you can at least drop a `last` in there and simplify the loop condition, if you use a `while`. Or how about a variant on `until`: `my $hash_has_undef = do { local $_; 1 until defined or not (undef, $_) = each %hash; defined; };` [download] Traded the flag variable for a double `defined` test on the last value fetched from the hash. Makeshifts last the longest.	[reply] [d/l]