Re^2: Questions about context

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Re^3: Questions about context by davido (Cardinal) on Jan 30, 2005 at 05:04 UTC
Hashes don't interpolate in double-quoted strings. That's the first reason it doesn't work. The second reason is that hashes need an even number of elements, and you're generating an odd number of elements. To illustrate both of those points, try the following: `my %hash = ( one => 1, two => 2 ); print "%hash\n"; # See, it doesn't interpolate. %hash = ( localtime )[5]; # Now you get a warning about uneven number +of elements.` [download] Far more than you ever wanted to know about string interpolation is described in perlop. Dave	[reply] [d/l]
Re^4: Questions about context by qq (Hermit) on Jan 30, 2005 at 19:53 UTC
Far more than you ever wanted to know about string interpolation is described in perlop. And yet more in MJD's Identity.	[reply]
Re^3: Questions about context by borisz (Canon) on Jan 30, 2005 at 02:06 UTC
No, that does not work. But you can write `print "@{[ %x ]}"` if you want. Boris	[reply] [d/l]
Re^3: Questions about context by ysth (Canon) on Jan 30, 2005 at 10:18 UTC
No, hashes don't interpolate into double-quoted strings in perl5. But you can use a scalar de-ref/ref: `print "year is ${\((localtime)[5]+1900)}!\n";` [download]	[reply] [d/l]
Re^4: Questions about context by nobull (Friar) on Jan 30, 2005 at 12:21 UTC
... you can use a scalar de-ref/ref: `print "year is ${\((localtime)[5]+1900)}!\n";` [download] True, but I've finally managed to get this mechanism excised from the FAQ because it is messy-looking and confusing. Many people looking at the that code (including the authors of early versions of the FAQ) would expect the expression to be evaluated in a scalar context. It is not. The expression in `\(EXPR)` is evaluated in a list context. Not, of course, that this makes any difference for the `+` operator.	[reply] [d/l] [select]
Re^5: Questions about context by ysth (Canon) on Feb 02, 2005 at 06:41 UTC
Then perhaps it would be better to advocate this approach instead of the more symmetrically beautiful `"@{[]}"`. It might lead more people to learn of the weird but wonderful context properties of \. (Sometimes people wonder why perl doesn't have a "list" operator corresponding to "scalar". The answer usually given is that it would rub the camel hair the wrong way, or that it is never needed. In point of fact it is sometimes needed when doing things like recursive calls to subroutines that return a map. And the way you spell `list(EXPR)` is `${\(EXPR)}`.)	[reply] [d/l] [select]