"Jonathan M Davis" <jmdavisp...@gmx.com> wrote in message news:mailman.538.1294690510.4748.digitalmar...@puremagic.com... > On Monday, January 10, 2011 10:46:55 Nick Sabalausky wrote: >> "Jim" <bitcir...@yahoo.com> wrote in message >> news:igfado$11g...@digitalmars.com... >> >> >> While writing and dealing with all that code I realized something: >> >> While >> >> programmers are usually heavily conditioned to think of >> >> case-sensitivity >> >> as >> >> an attribute of the comparison, it's very frequent that the deciding >> >> factor >> >> in which comparison to use is *not* the comparison itself but *what* >> >> gets compared. And in those cases, you have to use the awful strategy >> >> of "relying >> >> on convention" to make sure you get it right in *every* place that >> >> particular data gets compared. >> > >> > You have a point. Your case-sensitivity-aware string types will >> > guarantee >> > correctness in a large and complex program. I like that. Ideally >> > though, >> > they would only be compile-time constraints (i.e. not carrying any >> > other >> > data). >> >> Not carrying any other data means not caching the lowercase version, >> which >> means recreating the lowercase version more than necessary. So it's the >> classic speed vs. space tradeoff. I would think there would be cases >> where >> they get compared enough for that to make a difference, although I >> suppose >> we'd really need benchmarks to see. OTOH, there are certainly cases (such >> as my original motivating case) where the extra space is not an issue at >> all. > > Why is caching necessary? Shouldn't you just be able to use > std.string.icmp() > for comparisons internally, avoiding any copying or caching? That > shouldn't need > to duplicate anything. Or do you need to cache the lower-case version for > something other than comparison? >
Anything involving toHash (such as using Insensitive as an AA key) requires the use of a lower-case version. For anything else, you're probably right, icmp should be fine (Although I'd like to do a benchmark of icmp vs regular string comparison).