On Wednesday, 21 June 2017 at 13:53:02 UTC, MysticZach wrote:
On Wednesday, 21 June 2017 at 10:51:39 UTC, ketmar wrote:
there, of course, *IS* The difference. besides the aesthetical
one (seeing failed condition immediately "clicks" in your
head, and generic "assertion failed" message is only
frustrating), there may be the case when source code changed
since binary was built. here, line number gives you zero
information, and you have to checkout that exact version, and
go check the line. but when failed condition dumped, most of
the time it allows you to see what is wrong even without
switching to the old codebase (yes, "most of the time" is from
RL -- it is literally *most* of the time for me, for example).
How would you solve this issue? By pure chance, we're debating
this exact same issue right now in the DIP1009 thread [1].
Solutions:
1. Make more informative asserts the compiler default. This
threatens performance, which argues against it.
2. Status quo. Make people use whatever asserts they want,
e.g. fluent asserts [2]. This would mean that H.S Teoh's
proposed syntax for DIP1009 [3] would carry less weight, and
the existing proposal would carry more. Elegance is sacrificed
for the sake of versatility.
[...]
The verbose (existing) syntax already allows such versatility. I
see little reason to make the new syntax support that as well,
since there is (AFAIK) no proposal to drop the verbose syntax
(and I would be against dropping it, anyway).
I would prefer this:
- Keep the verbose (already existing) syntax with assert
statements in brace-delimited in/out blocks for people who need
versatility over elegance
- Make the new syntax elegant for the common cases (as discussed
in the DIP 1009 round 1 review thread), dropping explicit asserts
- Decouple the semantics of contract checking for the new syntax
from assert's implementation and define those semantics similar
to what I wrote here[1]
- Regarding contract conditions printed verbatim on failure: I
would support that in the implementation sketched by [1] via a D
version like `PrintViolatedContracts` and not couple that with
regular asserts at all
[1]
http://forum.dlang.org/post/[email protected]
