Revision as of 15:52, 20 July 2022 (view source) Nigel Galloway (talk \| contribs) (Realize in F#) ← Older edit		Revision as of 12:08, 21 July 2022 (view source) Nigel Galloway (talk \| contribs) (→‎{{header\|F_Sharp\|F#}}) Newer edit →
Line 293: <lang fsharp> // Monads/Writer monad . Nigel Galloway: July 20th., 2022 type Riter<'n~~,'g~~>=Riter of 'n * List<'gstring> ~~let bind=function \|(n,g)->Riter(n,[g])~~ let eval=function \|Riter(n,g)->(n,g) let compose f=function \|Riter(n,g)->let n,l=eval(f n) in Riter(n,List.append g l) let initV( n~~:float)~~=~~bind~~Riter(n,[sprintf "Initial Value %f" n]) let sqrt n=~~bind~~Riter(sqrt n,["Took square root"]) let ~~div2~~div n g=~~bind~~Riter(n/~~2.0~~g,[sprintf "Divided by 2%f" n]) let ~~incr~~add n g=~~bind~~Riter(n+~~1.0~~g,[sprintf "Added 1%f" n]) let result,log=eval((initV ~~5.0\|~~>>compose sqrt\|>>compose(add ~~incr\|~~1.0)>>compose(div ~~div2~~2.0))5.0) log\|>List.iter(printfn "%s") printfn "Final value = %f" result Line 309 ⟶ 308: Initial Value 5.000000 Took square root Added 1.000000 Divided by 2.000000 Final value = 10.618034 </pre> =={{header\|Factor}}== Factor comes with an implementation of Haskell-style monads in the <code>monads</code> vocabulary.

Monads/Writer monad: Difference between revisions

Monads/Writer monad (view source)