Follow-up Comment #1, bug #22109 (project coreutils): Could you provide some more justification than "would be nice" please?
Implementing the change you suggest would significantly complicate the implementation of tr, which is already quite fearsome; see for example the recent discussion of the correct processing of "tr [:lower:] [:upper:]" in locales where the number of upper-case letters is different to the number of lower-case letters. Such additional complexity doesn't come for free. Somebody has to implement it, the coreutils maintainers have to take the time to understand the new implementation, they have to maintain and fix bugs in it. Then the Info documentation and the manual page need to be updated to explain the changed functionality in such a way that any corner-cases are identified. For example, what does this do? tr -dc ABC -s Does that do the same as this? tr -d ABC -c -s What about "tr -d ABC -c -s 123"? Is 123 SET1 or SET2? I think the documentation task will be non-trivial. Non-trivial documentation will probably result, making it harder for people to understand. So everybody gets harder-to-understand documentation in the name of a convenience feature. The complex documentation and more complex implementation opens an opportunity for the documentation to describe something slightly different to the implementation. When somebody notices the problem, which should get fixed? But this feature could indeed be convenient. It could be sufficiently convenient for many people to use it a lot. Who will field their questions when their script doesn't work - or silently does something different - on other systems? In summary, maybe nobody should change any piece of software, ever. Except maybe to fix bugs. Carefully. :) _______________________________________________________ Reply to this item at: <http://savannah.gnu.org/bugs/?22109> _______________________________________________ Message sent via/by Savannah http://savannah.gnu.org/ _______________________________________________ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils