Allan Odgaard <ML@Top-House.DK> writes:
On 5. Apr 2004, at 21:22, David Abrahams wrote:
1. There's no way to search a stream for a match because a regex requires bidirectional iterators, so I have to do this totally frustrating line-by-line search. I think Spirit has some kind of iterator that turns an input iterator into something forward by holding a cache of the data starting with the earliest copy of the original iterator. Could something like that be added?
Added only to the regex library? sounds like it would be a very useful general purpose iterator adaptor, as there are also other (non standard) algorithms which need to backtrack over the input.
Of course. I just meant, "added for the benefit of the regex library".
2. Seems to me that if match objects could be converted to bool, we might be able to:
I can only second that, I am currently using my own regex library (some of my reasoning to be found in this c.l.c++.m thread: <http://tinyurl.com/2xnbd>), here I also allow implicit conversion to the iterator type, which allow code like:
iterator it = regex:find(first, last, ptrn);
Although I already did propose it for boost, but was told that it poses a problem with the ambiguity of an "empty" match at the end of the string and "no match at all" -- my argument here is that if one knows that the pattern might generate such a match (and one is interested in knowing about it), one just declares the result to be the match object. The former generally allows to code w/o all those if's to see if something was actually matched -- at least it has made much of my code simpler/shorter.
Sounds good to me. John? -- Dave Abrahams Boost Consulting www.boost-consulting.com