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Postings from August 2012
Hmmmm. In light of my arguments in defending bidrirctional overloading,
and of chromatic's observation regarding the relative ease of various types
of inversion-of-control on error reporting, I'm now convinced the
proposal should be:
______________________________________________________________________
Smartmatch (~~) table
=====================
$a $b Meaning
===== =================== ========================
Any ~~-overloaded [1] $b->ol_method($a, 'rev')
~~-ol Any [1] $a->ol_method($b)
Any undef ! defined $a
Any CodeRef, &{}-ol $b->($a)
Any Regexp, qr-ol $a =~ $b
Any unambiguous Num [2] $a == $b
Any unambiguous Str [3] $a eq $b
Any Any undef (with fatalizable warning)
[1] Includes junctions, whose overloading distributes the
smartmatch over their elements in their several ways.
[2] If $b has an internal numeric representation but no
internal string representation (or if some putative
internal flag assures us it was originally a number).
[3] If $b has an internal string representation but no
internal numeric representation (or if some theoretical
inner flag promises us it was initially a string).
The when construct
==================
Form Meaning
================== ==================================
when (EXPR) {...} if ($_ ~~ (EXPR)) {...; break}
when {BLOCK} {...} if ($_ ~~ sub{BLOCK}) {...; break}
No exceptions.
No special cases.
______________________________________________________________________
Damian
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