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Postings from October 2004
From: Rich Morin
October 24, 2004 22:26
Message ID: firstname.lastname@example.org
A fellow Perlie (NOT on this list) was ruminating on the idea of
generalizing the "Taint" capability into a first-class part of
the language. Something like allowing variables to log their
provenance, for later examination.
I came up with two possible approaches for this. One would act
a bit like the D (in DTrace) way of doing "conditional traces".
Another would act a bit like the "watchpoints" I've seen in a
debugger or three.
In any case, one way of doing something like this in Perl might
be to have the ability to register exceptions for a range of
quite ordinary behavior, such as entering or leaving a statement,
setting or even accessing a variable, etc.
I realize that this would slow the program down radically, but I
could see it being useful in tracking down oddball problems.
On a vaguely-related topic, I am reminded of another friend's
desire to be able to redefine floating point values as quartets
of values. Each operation would then be done using all possible
rounding options (in the IEEE standard) and the results checked
for "significant" variations. If anyone knows of a cute way to
do this in Perl 6, I'd be happy to hear about it...
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by Rich Morin