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* H.Merijn Brand <h.m.brand@xs4all.nl> [2015-09-10 17:45]:
> $x ~~ 42 --> $x == 42 ???
> $x ~~ "foo" --> $x eq "foo" ???
In $x ~~ $y with $y eq 42 you cannot tell whether the user wanted the
smartmatch to mean $x == 42 or $x eq 42. You can only tell that when the
user has given you a literal 42 vs a literal '42'.
So this can only work with literals. Therefore it would appear to be
useless: $x ~~ 42 with a literal 42 will never mean anything other than
$x == 42, so you can just as well write $x == 42 yourself. And it gets
worse: $x eq 42 is shorter and easier to type than $x ~~ '42' !
However, there is one case for it: if `when` is defined in terms of
smartmatch, then these rules would allow writing e.g.
given ($mode) {
when ('enable') { ... }
when ('disable') { ... }
# ...
}
That’s syntax I don’t really want to lose, and it would be nicer to say
that `when (EXPR)` is sugar for `if ($_ ~~ EXPR) { ...; break }` instead
of making `when` have its own very special cases over and above what ~~
does.
Regards,
--
Aristotle Pagaltzis // <http://plasmasturm.org/>
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