Re: optimization - exists should return a reference

Ah, but you don't avoid the 'once-and-only-once' with the modified exists either. You'd have to write something like:

    do {my $tmp = $_ -> {$client};
        return $$tmp if $tmp;} for $export_def->{'..client_default_ver
+sion'};
[download]

But then you have $tmp three times. And you can still leave the sigil off of $client and have strangely behaving code.

Abigail

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Re^3: optimization - exists should return a reference by Aristotle (Chancellor) on Jan 15, 2003 at 17:29 UTC
`do {my $tmp = $_ -> {$client}; return $$tmp if $tmp;} for $export_def->{'..client_default_version +'};` [download] I don't see any use of this proposed new exists (or any existance test at all for that matter) there. What are you trying to show? As BrowserUk said what I'd write then would be `return $$_ if $_ = exists $export_def->{'..client_default_version'}{$client};` [download] For the purpose of demonstration, you can even avoid assignments altogether: `{ return ${ exists $export_def->{'..client_default_version'}{$client} or last } }` [download] Yes, if I forget the sigil on `$client` I'll still get strange results, but having to get it right twice still offers more room for failure, not to mention the fact that if I get the sole instance of it wrong I will get consistent rather than intermittent failure which is far easier to notice and track. I stand by my point, this proposition is A Good Thing in terms of promotion of good programming practices. Makeshifts last the longest.	[reply] [d/l] [select]
Re: Re: optimization - exists should return a reference by BrowserUk (Patriarch) on Jan 15, 2003 at 14:31 UTC
Surely `exists $_->{$client} and return $_->{$client} for $export_def->{'..client_default_version'};` [download] Would just become `return $$_ if $_ = exists $export_def{'..client_default_version'}{$cli +ent};` [download] Which gives the desired once-and-once-only behaviour? Examine what is said, not who speaks. The 7th Rule of perl club is -- pearl clubs are easily damaged. Use a diamond club instead.	[reply] [d/l] [select]