inheritancef#recordtype

Creating an F# record type with a constant value

Let's say I have a record defined thusly...

type Employee = {Name : string; Salary : int}

and I want another type where Salary is fixed. I'd like to be able to say...

type Manager = {Name: string; Salary : int = 250000}

...but it seems I can't.

What options do I have to get this behaviour?

Solution

  • You can give your record a read-only property:

    type Manager = 
    {
        Name: string
    }
     member this.Salary = 250000

    FSI example:

    > let m = { Name = "Foo" };;

val m : Manager = {Name = "Foo";}

> m.Name;;
val it : string = "Foo"
> m.Salary;;
val it : int = 250000