Feature #5749
opennew method String#match_all needed
Description
The String class should contain an instance method 'match_all', which is a mixture of 'match' and 'scan'.
The method 'scan' is not a very powerful tool, its result(the yielding thing) is just a matched string or an array of captured strings.
p 'a1bc2de3f'.scan(/(.)\d(.)/) # [["a", "b"], ["c", "d"], ["e", "f"]]
If the regex argument contains groups, I even cannot get the whole matched string, and no information about the matched offsets.
So, a 'match_all' is very necessary. It scan the string, finding every matched, and yielding MatchData instance to the following block.
Here's a simple implemention in Ruby:
class String
def match_all(re,i=0)
if block_given?
while m = self.match(re,i)
yield m
i = m.end(0)
end
return self
else
ary = []
while m = self.match(re,i)
ary << m
i = m.end(0)
end
return ary
end
end
end
However, it is not efficient in the 'while m = self.match(re,i)' way, because it scan the string again and again. If string is UTF8-encoded and contains out-of-ASCII characters, I'm afraid getting the start index of it is so expensive.
So, I think a built-in 'match_all' method, which behaves just like 'scan' but yield MatchData, is needed.
Please consider it, thank you!