http://hackage.haskell.org/package/units is a pretty deep example of how to have type-safe units. On Wed, Aug 12, 2015 at 4:20 PM, Silvio Frischknecht < silvio.frischi@gmail.com> wrote:
Hi I'm experimenting with a unit system in haskell where users can add "base units". I want to reduce units after multiplication and bring it into a canonical form. The problem is what kind of types can the units have.
1)
data UnitA data UnitB
Problem: They can't be ordered so UnitA * UnitB can be compared to UnitB * UnitA, but I can't make a canonical form, which would make type inference a lot better.
2)
type UnitA = Zero type UnitB = Suc Zero
Problem: Now they can be ordered. But users can create conflicting "basic units"
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