On Wed, 30 Dec 2009 19:45:02 +0100, Andrei Alexandrescu <seewebsiteforem...@erdani.org> wrote:

I've wanted for a long time to move more stuff from std.string into std.algorithm. One issue that has kept me from doing that is the case issue, i.e. some string functions have mind/ignore case flavors that don't make sense for other data types. For example consider cmp() and icmp(): http://www.digitalmars.com/d/2.0/phobos/std_string.html#cmp or the recently changed indexOf: http://www.digitalmars.com/d/2.0/phobos/std_string.html#indexOf

It occurred to me that I can transfer the case sensitivity away from the algorithm into the data. To do so, we only need to define one more data type NoCase that behaves much like a dchar but defines opEquals to compare ignoring case. Then, we need to define a NoCase range that behaves like a bidirectional range of dchar but again uses case-insensitive comparisons. Add some garnishing and you get to write:

string a = "Hello, World!"
auto x = indexOf(a, nocase("world"));
assert(x == 7);

I'm quite excited about this because it modularizes the entire case business, opens strings to many algorithms, and allows generalization of string algorithms.

Well, that is until I hit http://d.puremagic.com/issues/show_bug.cgi?id=3659

Any thoughts and ideas would be appreciated.


Andrei

Sound nice. I've also wanted to see the two combined.
I take it the NoCase range is a lazy wrapper of a (d|w)?char range?

Some testing shows that 3659 can be sidestepped by making opEquals a
template function, or by creating more than one opEquals, where one
matches const bool( const ref typeof( this ) ).

--
Simen

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