Rafael Garcia-Suarez wrote:
Michele Dondi wrote:
I must say I've still not read all apocalypses, and OTOH I suspect that
this could be done more or less easily with a custom function (provided
that variables will have a method to keep track of their history, or, more
reasonably, will be *allowed* to have it), but I wonder if Perl6 may
include a builtin undo() function to recover values prior, say, to the
last assignement (or push() or, etc. etc.[*])
Difficulties: define "history" of a function w.r.t. threads; closures; and system side-effects (writing to files, locking them etc.)
In other words, if you want a transaction/rollback mechanism, use a suitable transaction library that fits your needs, not a half-baked kludge built into the base language.
Besides we already have MTOWTDI with local() and hypotheticals.
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