>>>>> "DTC" == Deven T Corzine <[EMAIL PROTECTED]> writes:
DTC> The pattern in question is "b.*?d". Obviously, this matches "b",
DTC> followed by something else, followed by "d". What "something
DTC> else" should be is the issue at hand. That portion of the regexp
DTC> is just ".*?" -- the "." matches any character (except newlines,
DTC> depending on the mode), the "*" modifies the "." to match "zero
DTC> or more" of "any character", and the "?" modifies the ".*" to
DTC> match "zero or more" of "any character", but "matching the
DTC> minimum number of times possible". Hence, the ".*?" can be
DTC> summarized as "match anything, but keep the match as short as
DTC> possible".
DTC> TAKEN IN ISOLATION, the most natural interpretation for the
DTC> programmer to make, at this high semantic level, is that it will
DTC> match "bccccd" rather than "bbbbccccd", because the ".*?" is
DTC> expected to match as little as possible (though as much as
DTC> necessary), and "cccc" is as little as it can possibly match
DTC> while allowing the entire regexp to match. "bbbbccccd" is a
DTC> longer match, and counterintuitive compared to the semantic
DTC> description of what "b.*?d" should match.
just add the semantic part of leftmost or first and you have your
answer. it is defined that way in the current semantics as well as in
the implementation. regardless, having the semantics of your way would
entail finding ALL possible matches and then scanning them for the
shortest one. there is no other way to define that behavior than
that. how could you find the true shortest match without finding all of
the matches first? the leftmost/first semantic eliminates that problem.
so please add those words and then restate your argument. you can't. the
result you want does not jibe with first or leftmost. it is a different
semantic. and the current one is used for many reasons including
history, simplicity of semantics and even (drat!) implementation and
speed.
as for perl6 doing what you want, write a regex engine and plug it
in. but the default perl6 regexes should behave the same as perl5's for
all the right reasons including backwards compatibility.
uri
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