| open Microsoft.FSharp.Quotations | |
| // <@ fun x -> (% <@ x @> ) @> ~ lambda (fun x -> x) | |
| let lambda (f : Expr<'T> -> Expr<'R>) : Expr<'T -> 'R> = | |
| let var = new Var("__temp__", typeof<'T>) | |
| Expr.Cast<_>(Expr.Lambda(var, f (Expr.Cast<_>(Expr.Var var)))) | |
| // fixed-point combinator | |
| let rec fix : (('Τ -> 'R) -> ('Τ -> 'R)) -> 'Τ -> 'R = fun f x -> |
Copyright © 2016-2017 Fantasyland Institute of Learning. All rights reserved.
A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.
val square : Int => Int = x => x * x
| #lang racket/base | |
| ;; Monads in Racket, including polymorphic bind, return and fail. | |
| ;; Haskell-like do-notation. | |
| (provide define-monad-class | |
| (struct-out monad-class) | |
| monad? | |
| gen:monad | |
| monad->monad-class | |
| determine-monad |
| #Newbie programmer | |
| def factorial(x): | |
| if x == 0: | |
| return 1 | |
| else: | |
| return x * factorial(x - 1) | |
| print factorial(6) | |
| #First year programmer, studied Pascal |