CODEWITHSUNDEEP
f#units-of-measurement
nicolas
nicolas

Reputation: 9805

Composite units of measure in F# for matrix operation check

One of the serious use case for units of measure is matrix operations: The inner product of a matrix a*b with c*d is only valid when b = c, etc....

However, I dont see any constructs for 'composite units' such as the one that would be required.

Do we have any way of having this checked by the type system in F# ?

Upvotes: 2

Views: 215

Answers (1)

desco
desco

Reputation: 16782

disclaimer: sent from phone => can contain errors

I'd say that this check in some way can be achieved using UoM or phantom types:

[<Measure>] type s
type M<[<Measure>]'w, [<Measure>] 'h>() = 
    static member (*) (a : M<'a, 't>, b : M<'t, 'b>) : M<'a, 'b> = failwith "NYI"
let x = M<s ^ 3, s ^ 3>()
let y = M<s ^ 3, s>()
let z  = x * y // M<s ^ 3, s>

However question is: how convinient it will be to use...

Upvotes: 4

Related Questions