Overflow error in EuclideanRing

[jacereda]

Checking 'Submultiplicative euclidean function' law for EuclideanRing
999/1000 test(s) passed.
/Users/jacereda/src/purescript/purescript-quickcheck-laws/output/Control.Monad.Eff.Exception/foreign.js:29
    throw e;
    ^

Error: Test 90 (seed 2114546612) failed: 
Test returned false

[hdgarrood]

Which type is this? Also, how do you know it's an overflow error?

[jacereda]

Int and I assume it's an overflow because the product can easily overflow with two arbitrary ints.

[jacereda]

To reproduce it easily, just increase the number of iterations for submultiplicative in checkEuclideanRing, something like 10000 suffice.

[hdgarrood]

Right, I guess we should just remove that test from this repo's test suite then.

[jacereda]

Or perform an overflow check?

[hdgarrood]

We can't do that with just a EuclideanRing constraint, though, surely?

[jacereda]

nope, I guess Ord and Bounded would be required.

[hdgarrood]

Right - and there are perfectly good euclidean rings which are neither Ord nor Bounded; gaussian integers and polynomials over a field, for example.

[jacereda]

Looks like we can do without Bounded:

#30

[JordanMartinez]

As discussed in #30 (comment)

Looks like the next action is to drop the overflow check and instead wrap Int in a newtype that limits how large the initial generated Int can be, so that an overflow error cannot occur. That would fix the false positive.