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Postings from March 2001
<abigail@foad.org> writes: >> So my stance is that $1 is lazy, if you want/need a copy then write "$1". > >The problem isn't $1. $1 is just a figurant in this drama, and its role >could be played by any other variable. Okay - I said that a while back. >The lead role is &&. The example >might be bad, but if you think that's caused by &&, you are missing the >point. It's && that returns aliases, instead of the expected values. >Here's another example that shows the problem lies with &&: > > print +(($x = 2) && $x) + (($x = 3) && $x); > >That will print `6', not `5'. Or is "$x" lazy as well? Probably not. > >As for "$1 is lazy", I say Eh? The word `lazy' turns up a whopping four >times in the 5.6.0 pods, and none of them in the meaning you are using. Sorry, a more perl-ish usage would be 'magical' but using that in normal english has wrong conotations. >Lazy evaluation has a well defined meaning, but it belongs in the class >of functional languages, where order of evaluation is not important. > >In the class of imperative languages, lazy evaluation doesn't make sense, >as the side-effects, and the order in which they happen are vital to write >programs. None the less perl's 'magical' variables share the order of evaluation issues with "lazy evaluation". $1 does not "become" the matched range until it is used. > > > >Abigail -- Nick Ing-Simmons <nik@tiuk.ti.com> Via, but not speaking for: Texas Instruments Ltd.Thread Previous | Thread Next