Add TotalityCheck and tests #103
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@@ Coverage Diff @@
## master #103 +/- ##
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+ Coverage 71.25% 73.07% +1.82%
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Files 37 38 +1
Lines 2007 2206 +199
Branches 47 59 +12
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+ Hits 1430 1612 +182
- Misses 577 594 +17
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This isn't perfect, but it is already big enough. I'm going to merge then look for more tests to gain confidence. I think it is important to note: we actually don't need perfect set operations on patterns: we just need to accurately detect if any branches are missing. Giving an exact minimal covering of the missing branches is not required. |
| * then make: | ||
| * Struct(d1, _, _), Struct(_, d2, _), ... | ||
| */ | ||
| def poke[M[_]: Applicative, A](items: List[A])(fn: A => M[List[A]]): M[List[List[A]]] = |
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TODO: as a follow up, this can be handled recursively: we already have handling below. I'm also suspect of this method.
When we expanded the power of the patterns the naive exhaustivity checking was removed because it wouldn't work.
Since then, we have actually been rolling with no match exhaustivity checking.
This adds code to check all patterns are exhaustive. It seems that with the current pattern language, we actually don't need to typecheck to do totality checking, which is interesting. That might be a good property to maintain (and maybe is always, or almost always true...)
This turns out to be a bit tricky and I had to derive some formulas, which I just left in the comments. I have pretty good tests of the checker, but will see a better test when I wire it into the compiler.