let add a b = a + b
> let add a b = a + b;;
val add : int -> int -> int
> add 2 3;;
val it : int = 5
> add 2.0 3.0;;
add 2.0 3.0;;
----^^^
stdin(3,5): error FS0001: This expression was expected to have type
int
but here has type
floatHow do we make the function acceptable other numeric types?
module ExamplesNormally, it is enough that there is just one module declaration in the first line. If you want to declare more than one modules or nested modules, module declaration is in below lines and it requires =.
let helloWorld() = "Hello World"
module Greeting =
let helloWorld() = "Hello Module World"
module Inner =
let helloWorld() = "Hello Inner Module World"
namespace Program
open Examples
[<Class>]
type Simple() =
static member execute() =
System.Console.WriteLine("Examples.helloWorld() : {0}", helloWorld())
System.Console.WriteLine("Examples.Greeting.helloWorld() : {0}", Greeting.helloWorld())
System.Console.WriteLine("Examples.Greeting.Inner.helloWorld() : {0}", Greeting.Inner.helloWorld())
0
[<Class>]Function typeof gets the concrete type of type parameter.
type Reflector<'a>() =
member r.GetMembers() =
let ty = typeof<'a>
ty.GetMembers()
let rflc = new Reflector<System.Math>()
// usage
Array.iter (fun it -> System.Console.WriteLine(it.ToString())) (rflc.GetMembers())
[<Class>]
type StaticReflector() =
static member GetMembers<'a>() =
let ty = typeof<'a>
ty.GetMembers()
// usage
Array.iter (fun it -> System.Console.WriteLine(it.ToString())) (StaticReflector.GetMembers<System.Math>())
[<Interface>]Interface can inherit another interfaces multiply.
type IDrinker =
inherit System.IComparable
inherit System.IFormattable
abstract Drink : unit -> unit // method definition of interface
abstract FavoriteDrink : string // property definition of interface
[<Class>]hash and compare are utility functions for implementing GetHashCode() and Equals(other) explicitly.
type DrinkingPerson(fn, ln, a) =
inherit System.Object()
interface IDrinker with
member this.CompareTo(other) =
let other = other :?> DrinkingPerson
let tln : string = this.LastName
let ln = tln.CompareTo(other.LastName)
if ln <> 0 then
let tfn : string = this.FirstName
let fn = tfn.CompareTo(other.FirstName)
if fn <> 0 then
let ta : int = this.Age
ta.CompareTo(other.Age)
else
fn
else
ln
member this.ToString(s:string, fp:System.IFormatProvider):string =
"Not interesting enough to implement yet"
member this.Drink() =
System.Console.WriteLine("Yep")
member this.FavoriteDrink =
"Grapefruit juice"
override this.GetHashCode() =hash(fn, ln, a)override this.Equals(other) =compare this (other:?>DrinkingPerson) = 0member p.FirstName = fn
member p.LastName = ln
member p.Age = a