[cmake-developers] string SUBSTRING TRUNCATE mode

[Brad King]

On 11/11/2014 06:16 PM, Domen Vrankar wrote:
> string(SUBSTRING <string> <begin> <length> <output variable> [TRUNCATE])
[snip]
> string(SUBSTRING ${test_str} 2 6 substr TRUNCATE)
> 
> If length is set to a higher value than the length of the original
> string the substring is still created but its end is the end of
> original string.

The functionality makes sense.  Python 'abcd'[2:6] does this
automatically.  I agree the name TRUNCATE is hard to follow
because I had to read the example to understand the command.
SHORTEN may have the same problem.  Other brainstorming ideas:

 (CLIP|INTERSECT|TOLERANT)(_RANGE)?

Another option is to just start tolerating out-of-range indexes.
Since it is currently an error there would be no compatibility
problem (except that someone may write code using a newer CMake
that then breaks on an older version).

> If this functionality would be welcome I'll write the tests and
> documentation.

Yes.  After the naming bikeshed is painted then tests can go in
Tests/RunCMake/string/*

Thanks,
-Brad