Read from Console in F#

问题:

Does anyone know if there is a builtin function for reading from the console likewise to the printfn function? The only method I've seen so far is using System.Console.Read() but it doesn't feel as functional as using a construct like printfn is.

回答1:

It is indeed a shame that there is no such built-in function. However, as Brian mentioned in a comment on Benjol's answer, it is possible to build a scanf function yourself. Here's a quick sketch of how one might define a sscanf variant, although only %s placeholders are implemented:

open System open System.Text open System.Text.RegularExpressions open Microsoft.FSharp.Reflection  let sscanf (pf:PrintfFormat<_,_,_,_,'t>) s : 't =   let formatStr = pf.Value   let constants = formatStr.Split([|"%s"|], StringSplitOptions.None)   let regex = Regex("^" + String.Join("(.*?)", constants |> Array.map Regex.Escape) + "$")   let matches =      regex.Match(s).Groups      |> Seq.cast<Group>      |> Seq.skip 1     |> Seq.map (fun g -> g.Value |> box)   FSharpValue.MakeTuple(matches |> Seq.toArray, typeof<'t>) :?> 't   let (a,b) = sscanf "(%s, %s)" "(A, B)" let (x,y,z) = sscanf "%s-%s-%s" "test-this-string"

回答2:

As far as I know, no.

It would be handy for code golf :)

回答3:

Combination of TryParse() and split/regex is what you can use "out of box".

P.S. i've seen http://www.codeproject.com/KB/recipes/csscanf.aspx and it works ;)

转载请标明出处:Read from Console in F#

文章来源: Read from Console in F#

跳转到

• 问题:
• 回答1:
• 回答2:
• 回答3:

Close