Making all strings UTF ranges has some risk of WTF

[Michel Fortin]

On 2010-02-04 12:19:42 -0500, Andrei Alexandrescu 
<SeeWebsiteForEmail at erdani.org> said:

> bearophile wrote:
>> Simen kjaeraas:
>>> Of the above, I feel (b) is the correct solution, and I understand
>>> it has already been implemented in svn.
>> 
>> Yes, I presume he was mostly looking for a justification of his ideas
>> he has already accepted and even partially implemented :-)
> 
> I am ready to throw away the implementation as soon as a better idea 
> comes around. As other times, I operated the change to see how things 
> feel with the new approach.

Has any thought been given to foreach? Currently all these work for strings:

	foreach (c; "abc") { } // typeof(c) is 'char'
	foreach (char c; "abc") { }
	foreach (wchar c; "abc") { }
	foreach (dchar c; "abc") { }

I'm concerned about the first case where the element type is implicit. 
The implicit element type is (currently) the code units. If the range 
use code points 'dchar' as the element type, then I think foreach needs 
to be changed so that the default element type is 'dchar' too (in the 
first line of my example). Having ranges and foreach disagree on this 
would be very inconsistent. Of course you should be allowed to iterate 
using 'char' and 'wchar' too.

I think this would fit nicely. I was surprised at first when learning D 
and I noticed that foreach didn't do this, that I had to explicitly has 
for it.

-- 
Michel Fortin
michel.fortin at michelf.com
http://michelf.com/