Re: [PATCH] Re: replace-in-string infloops

Aidan> Well-defined by Perl and other regexp engines, you mean? No, well-defined in abstract algebra and language theory. The rest of that crap is mere implementation. Aidan> Its Perl equivalent does do what you say, though (ignoring Aidan> that your example result didn’t pay attention to the Aidan> starting anchor empty match); There is no empty match at the starting anchor, there is a nonnull match there. IMO, Perl is broken. So is PHP. Maybe we'd better check POSIX, I could very likely be wrong: the Perl guys are unlikely to screw up on regexps! On second thought, Python gives the answer I prefer: 'bcb' and furthermore defines the operation in language theory terms, not via a reference implementation: `sub(pattern, repl, string[, count])' Return the string obtained by replacing the leftmost non-overlapping occurrences of PATTERN in STRING by the replacement REPL. If the pattern isn't found, STRING is returned unchanged. ("Leftmost non-overlapping" actually means "if matches overlap, the leftmost is replaced, and any matches that overlapped it are ignored", according to the Python implementation: 'bba' That's what I want it to mean. ;-) Aidan> [They are.] Aidan> Whee. Thanks for checking! Now comes the fun. -- Institute of Policy and Planning Sciences http://turnbull.sk.tsukuba.ac.jp University of Tsukuba Tennodai 1-1-1 Tsukuba 305-8573 JAPAN Ask not how you can "do" free software business; ask what your business can "do for" free software.