Question

Given a class such as:

type MyClass() =
    member this.Greet(x) = printfn "Hello %s" x

is it appropriate to initialize instances using

let x = new MyClass()

or without the new?

Also, when is the use of a new constructor more useful than a do binding with parameters supplied to the type definition?

Answer 1

My pattern in F# for using new is to only do so when the type implements IDisposable. The compiler special cases this use and emits a warning if new is omitted.

So in your case I would not use new. But with the following I would

type OtherClass() =
  ...
  interface System.IDisposable with 
    member this.Dispose() = ...

let x = new OtherClass()