[CMake] FIND sub-command to the STRING command

[Tim Hütz]

Ok, I've implemented a forward search (finds the first occurrence of the substring) and a reverse search (which finds the last occurrence of a substring). Should I open a ticket (with adding the required paches) for suggesting this for one of the next CMake releases or how should I proceed? The idea of a STRING( FIND REGEX ...) is nice too. I'm working on it as soon as I have some free minutes :)

Am 04.02.2011 um 16:02 schrieb Michael Wild:

> Exactly. The single-character matching would then just be a special
> case. If you want to get fancy, having a string(FIND REGEX) command
> would also be nice ;-)
> 
> Michael
> 
> On 02/04/2011 03:31 PM, Tim Hütz wrote:
>> Mhh, okay. With substring matching you mean that I can get the position of the first occurrence of a word or sub-sentence, am I right?
>> 
>> 
>> Am 04.02.2011 um 13:32 schrieb Michael Wild:
>> 
>>> On 02/04/2011 12:49 PM, Tim Hütz wrote:
>>>> I don't think that the speed-factor was important in this case. A complete CMake run takes about 25 seconds to run (in my case) and I see no influence in the processing time with my suggested patch or the regular expression sample provided by Michael. I thought that my solution is a bit more intuitive, but I don't know if this is really important for CMake. If you use the provided patch, you can do something like
>>>> 
>>>> PROJECT( "STRING FIND command" )
>>>> SET( TESTSTRING "This is a test" )
>>>> STRING( FIND ${TESTSTRING} "a" APOSITION )
>>>> MESSAGE( STATUS "Position of character 'a' is ${APOSITION}" )
>>>> 
>>>> Regards,
>>>> Tim
>>>> 
>>>> Am 04.02.2011 um 12:00 schrieb SF Markus Elfring:
>>>> 
>>>>>> mhh, yeah, thats a good idea. Ok, I'll use this for doing a "STRING( FIND ...)" :) It was just an idea to share this patch with you, but you're right. Its easier doing this with regular expressions.
>>>>> 
>>>>> Can it be that your implementation was faster than a complete regex application for your use case?
>>>>> 
>>>>> Are there any remarkable differences in the corresponding execution speed and performance characteristics?
>>>>> 
>>>>> Regards,
>>> 
>>> I just wanted to point out that this particular use-case can be handled
>>> by a regular expression. I still think that a string(FIND) command would
>>> be useful, although it would be even more so if it did substring matching.
>>> 
>>> BTW, I just had an idea how to find substrings with regexes, but it is
>>> even more tedious:
>>> 
>>> set(str "Hello Tim. How are you Tim?")
>>> set(pos -1)
>>> if(str MATCHES "(Tim.*)")
>>> string(LENGTH "${str}" l1)
>>> string(LENGTH "${CMAKE_MATCH_1}" l2)
>>> math(EXPR pos "${l1}-${l2}")
>>> endif()
>>> 
>>> This finds the position of the first occurence of "Tim". Another
>>> alternative, without math(EXPR) is:
>>> 
>>> set(str "Hello Tim. How are you Tim?")
>>> set(pos -1)
>>> string(REGEX REPLACE "Ali.*" "" tmp "${str}")
>>> if(NOT "${tmp}" STREQUAL "${str}")
>>> string(LENGTH "${tmp}" pos)
>>> endif()
>>> 
>>> Michael
>>> 
> _______________________________________________
> Powered by www.kitware.com
> 
> Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html
> 
> Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ
> 
> Follow this link to subscribe/unsubscribe:
> http://www.cmake.org/mailman/listinfo/cmake

-------------- next part --------------
A non-text attachment was scrubbed...
Name: PGP.sig
Type: application/pgp-signature
Size: 833 bytes
Desc: Signierter Teil der Nachricht
URL: <http://www.cmake.org/pipermail/cmake/attachments/20110204/22c630be/attachment-0001.pgp>