Today's programming challenge - How's your Range-Fu ?

[John Colvin via Digitalmars-d]

On Friday, 17 April 2015 at 18:41:59 UTC, Walter Bright wrote:
> On 4/17/2015 9:59 AM, H. S. Teoh via Digitalmars-d wrote:
>> So either you have to throw out all pretenses of 
>> Unicode-correctness and
>> just stick with ASCII-style per-character line-wrapping, or 
>> you have to
>> live with byGrapheme with all the complexity that it entails. 
>> The former
>> is quite easy to write -- I could throw it together in a 
>> couple o' hours
>> max, but the latter is a pretty big project (cf. Unicode 
>> line-breaking
>> algorithm, which is one of the TR's).
>
> It'd be good enough to duplicate the existing behavior, which 
> is to treat decoded unicode characters as one column.

Code points aren't equivalent to characters. They're not the same 
thing in most European languages, never mind the rest of the 
world. If we have a line-wrapping algorithm in phobos that works 
by code points, it needs a large "THIS IS ONLY FOR SIMPLE ENGLISH 
TEXT" warning.

Code points are a useful chunk size for some tasjs and completely 
insufficient for others.