On Tuesday, 5 June 2018 at 06:45:31 UTC, Petar Kirov [ZombineDev]
wrote:
On Monday, 4 June 2018 at 15:48:35 UTC, DigitalDesigns wrote:
Does D have any methods of validating code in a natural manner
besides unit tests and contracts?
I'm specifically thinking of validating mathematical
calculations and boolean operations that could depend on very
improbable scenarios but are technically invalid logic.
These issues tend to creep up in calculations that involve
floating points due to various reasons or comparisons that
mistakenly use > for >= or vice versa.
If I have a variable such as a buffer which has a length and
an offset in to that buffer is calculated using double
precision then rounding errors could cause the offset to
except the length and create an access violation.
To be able to theoretically test all the possibilities all
valid inputs would need to be checked. One can setup unit
tests to test these possibilities but it can be difficult to
cover all cases in even a semi-complex program.
Just curious if something exists that allows for mathematical
validation such code in an relatively canonical way. This
isn't too hard for pure functions but dealing with non-pure
functions can be a pain.
Perhaps not quite what you're looking for, but I think you
would be interested in the LLVM fuzzing part of Johan Engelen's
talk at DConf 2018:
https://www.youtube.com/watch?v=GMKvYrjaaoU (at around 34:30).
Sorta, but not fuzzing because that is too spare. Rather than
picking a random point in a billion dimensional vector space bit
is sort of works only on the surface of possible values. Which he
addresses initially being the problem and is similar to what I'm
looking for.
The idea though is problems almost always occur on edge cases so
there is no need to check everything inside an interval but only
the edge cases.
if (x < 10)
one only needs to check if x = 9, 10, 11 but not 4, 5, etc.
Of course, in more complex cases it might be difficult to
determine this so maybe the method in the video is more general
purpose. It seems to have the capabilities to have a bit more
intelligent checking though so yeah, this seems to be what I was
looking for!
Thanks!
In any case
