Pattern Matching of Units of Measure in F#

Posted by Oldrich Svec on Stack Overflow See other posts from Stack Overflow or by Oldrich Svec
Published on 2010-04-19T09:06:54Z Indexed on 2010/04/19 9:13 UTC
Read the original article Hit count: 187

Filed under:

F#

|

pattern-matching

|

units-of-measurement

This function:

let convert (v: float<_>) =
  match v with
  | :? float<m> -> v / 0.1<m>
  | :? float<m/s> -> v / 0.2<m/s>
  | _ -> failwith "unknown"

produces an error

The type 'float<'u>' does not have any proper subtypes and cannot be used as the source of     a type test or runtime coercion.

Is there any way how to pattern match units of measure?

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