J has "PCRE" regular expressions: require 'regex' url=: 'http://www.jsoftware.com/help/pcre/pcrepattern.html' >('http://[^/]+'&rxmatch rxcut ]) url
http://www.jsoftware.com /help/pcre/pcrepattern.html Now.. regular expressions seem like they ought to be a natural fit for J - if nothing else, the sort of people who turn up their nose at J syntax are probably either (a) so inured to regular expressions that they forget how they look, or (b) can't stand regular expressions. That said... PCRE stands for "perl compatible regular expressions" and J is missing a significant feature from perl's implementation: string interpolation. Perl has a string language where you can specify variables to plug into the string, and PCRE ties into that mechanism. J is significantly more verbose for this kind of thing. In other words, in perl, I could do this: $url=~ s{http://([^/]+)}{https://$1/wiki}; and if $url were the value of url, above (in perl scalar variable names begin with $ and strings are treated as scalars - perl does not have J's concept of rank and instead approximates it with the rank indicator hard-coded into the variable name), then the above sentence would modify its value to be: https://www.jsoftware.com/wiki/help/pcre/pcrepattern.html Here's some equivalent (explicit) J: if. {:,M=. 'http://([^/]+)' rxmatch url do. segs=. M rxcut url mid=. (,:({:-{.@{.)M) rxcut 1{::segs url=. ;}.(<'https://',(1{::mid),'/wiki') 1} segs end. As you can see, it's a bit more complex. So ... I'm not going to tackle writing such a thing - at least, not tonight. But that's something that might be nice - support for a string interpolation language, including tie-in support for the jregex locale. (I am mostly writing this to organize my thoughts - as you can see, this topic is messy enough in J that organizing thoughts is probably a good idea.) (And, yes, this particular task could be accomplished more easily in J - my actual task is more complicated and needs a more involved regular expression. I'm just outlining what I see as an issue.) Thanks, -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
