Hello bearophile,
BCS:
All the issues you address up to where you propose ctputs are bugs in
DMD, not pragma(msg,...) as for ctputs as a /replacement/ see my
replay to the bug.
Thank you for this answer and the answer in bugzilla. I explain the
problems I find while I program in D, and sometimes I try to give a
starting point for a solution, but usually it's not hard to find
solutions better than the ones I suggest.
I have written an answer in Bugzilla, I don't know if it's enough.
you will not convince me that what it currently does is less than
/very useful/.
You are right :-)
My minimum requirements for a pragma(msgm...) replacement would be
that it take any expression that results in an immutable(char[]) and,
at compile time (and only compile time) during the semantic pass
(while the code is processed, not evaluated) output the string.
I'd like to ctputs() to act as std.c.stdio.puts() if the function is
run at run time.
The major cases where your ctputs fails on this are inside a function
that
can be evaluated via CTFE:
- If placed in a RT loop it could be evaluated to many times.
- If placed in a code path that isn't hit via CTFE, it never outputs
anything.
- If the function gets run at RT, then you need to add a guard to
prevent
it from generating output at RT.
This is by design.
Understood, and I see it's value. I'm not going to argue for not having ctputs()
but I want (need?) a way to have the other option. I don't think these can
be combined (but I could be wrong). Just as a point to consider; it might
be reasonable to implement ctputs in terms of a combination of a compile
time only puts and a runtime only puts. Either the runtime/compile time version
or the compile time only version can be derived from the other but deriving
the former seems cleaner than deriving the latter.
But I understand your point, ctputs seems designed for a purpose
different than pragma(msg), it doesn't seem a replacement. ctputs is
meant as a way to print strings from function if you call the function
both at runtime or compile time with CTFE. pragma(msg) is meant to
show a message at compile time. So pragma(msg) needs to be debugged
and then kept.
Good. We agree.
I probably have update the bug report, and I'd like to split it in a
pragma(msg) bug report (essentially to make it test its input argument
better), plus an enhancement request for a ctputs() probably in
std.intrinsic :-)
Souinds like a good way to go.
--
... <IXOYE><
