Back to Questions
750
views1
comment
sequencing construct
f#

The following code issues a warning FS0020: This expression should have type 'unit', but has type 'DirectoryInfo'.

How can I sequence expressions to avoid such warnings?

Thanks.

1
2
3
4
5
6
7

#light
open System.IO
match Directory.Exists("c:/mydir") with
| true -> ()
| false -> 
    Directory.CreateDirectory("c:/mydir")
    printfn "%s\n" "Directory created with success."
.

That's because of CreateDirectory... hence you may use :

1
2
3
4
5

match Directory.Exists("c:/mydir") with
| true -> ()
| false -> 
    ignore <| Directory.CreateDirectory("c:/mydir")               
    printfn "%s\n" "Directory created with success."

or, equivalently,

1
2
3
4
5

match Directory.Exists("c:/mydir") with
| true -> ()
| false -> 
    let _ = Directory.CreateDirectory("c:/mydir")               
    printfn "%s\n" "Directory created with success."
By on 7/14/2008 5:43 AM ()

    Topic tags

    IntelliFactory Offices Copyright (c) 2011-2012 IntelliFactory. All rights reserved.
    Home | Products | Consulting | Trainings | Blogs | Jobs | Contact Us | Terms of Use | Privacy Policy | Cookie Policy     		Built with WebSharper