f#

I have the following discriminated union: type ActCard = Cellar of card list | Chapel of (card option * card option* card option* card option) | Smithy | Spy of (card -> bool * card -> bool) It had structural equality until I added the card -> bool to Spy . This question is helpful for how to do custom equality for records. However, I'm not sure how best to implement it in this situation. I would prefer to not have to enumerate each case in ActCard : override x.Equals(yobj) = match x, yobj with | Spy _, Spy _ -> true | Cellar cards, Cellar cards2 -> cards = cards2 (* ... etc *) What is a

What is the difference (if any) between these two F# type signatures? UseTheStream<'a when 'a :> Stream> : 'a -> unit and UseTheStream : (stream : Stream) -> unit Do they mean the same thing in this case? msdn says the following about the (:>) Type Constraint type-parameter :> type -- The provided type must be equal to or derived from the type specified, or, if the type is an interface, the provided type must implement the interface. This would indicate that the two signatures are saying the same thing. So Functionally, how are they different? Daniel They are different. Most importantly, the

I have an expression using pipe operator that converts the value to string and then to bool, however sometimes the original value can be null. How can I use the pattern matching or something else to assume false when the value is null? type kv = Dictionary<string, obj> let allDayEvent (d: kv) = d.["fAllDayEvent"] |> string |> bool.Parse Anton Schwaighofer There's quite a few places where you can safeguard via pattern matching: dictionary lookup, casting, parsing. Here's an example with all of those: let allDayEvent (d: kv) = match d.TryGetValue "fAllDayEvent" with | true, v -> match v with |