improve tracing: check/log pattern matches on unknown/known data about co4 HOT 4 CLOSED

simple proposal (a.k.a. Hack) for checking:

instead of case x of ... allow to write case known x of where

• semantically known = id
• but for compiling: only generate the code for the case that the constructor is statically known (will throw an exception if this is not the case, exception should contain line number or similar)

come to think of it - this known x could be put anywhere (not just under the case) and it will just check (at runtime) that the top constructor indeed is known.

from co4.

known x

148c8a6 provides assertKnown and assertDefined with the given semantics (the name known is already taken by the allocators). Both functions require import CO4.Prelude.

from co4.

commit 534ab80 contains very simple constraint that recurses on a known list (with unknown elements)

constraint s xs = eqNat8 s ( summe xs)

summe xs = case assertKnown xs of
    [] -> nat8 0
    x:xs' -> plusNat8 x (summe xs')

when running it with assertions enabled, I get an exception:

ghci CO4/Test/Assert.hs

*Main> main
Start producing CNF
*** Exception: EncodedAdt.Overlapping.constantConstructorIndex: no flags

where I was expecting that it works without exception.

from co4.

fixed by f823290

from co4.