-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 7/31/10 11:17 , Mark J. Reed wrote: > What if you say 'when test($_)'? Or just 'when &test'? How do you > smart match on a function: call the func with the target as argument > and use the return value, or call it without any argument and compare > the return value to the target? Does arity matter? Or whether the > function is declared to return a Boolean value/called in a Boolean > context?
As I understand the spec: given <expr> sets $_ to <expr> when test() calls test with no argument when test($_) calls test with the topic when &test uses the function object &test It seems like this leaves $_ in an odd place, no longer really a "topic", just a sort of shorthand which is sometimes implied (see for example ".foo" as calling method foo() of $_) and sometimes not (given/when). "when" as currently specced seems like it's just a synonym for "if". Overgeneralization seems to have left $_ and "when" in a rather muddy spot. I feel like if the point of given/when is an overly general case statement (as it currently seems to be), then using $_ is a Huffmanization waste (surely $^a is good enough?) and confuses what $_ is supposed to mean, and if the point is to be a general case statement then "when <expr> <block>" should smartmatch <expr> against $_ instead of evaluating it with $_ available as a shorthand/topic. Thus the confusion in the message that started this thread: most people expect the latter behavior, but are getting the former which feels like a Huffmanization failure in addition to confusing the question of implicit vs. explicit topicalization/$_. (Am I making any sense here? I know what I'm trying to say, but am unsure that I am describing it sensibly.) - -- brandon s. allbery [linux,solaris,freebsd,perl] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.10 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkxURYEACgkQIn7hlCsL25X/4QCfT3xbqtyY9sJ8UvT0VycKqetf nYgAnR5dw7sDNsMj6hSnwHYT90TzFxia =u4Hj -----END PGP SIGNATURE-----
