Operators.( <| )<'T,'U> Function (F#)
Applies a function to a value, the value being on the right, the function on the left.
Namespace/Module Path: Microsoft.FSharp.Core.Operators
Assembly: FSharp.Core (in FSharp.Core.dll)
// Signature:
( <| ) : ('T -> 'U) -> 'T -> 'U
// Usage:
func <| arg1
Parameters
func
Type: 'T -> 'UThe function.
arg1
Type: 'TThe argument.
Return Value
The function result.
Remarks
The function is referred to as the backward or reverse pipe operator.
Example
The following example demonstrates the use of the <| operator.
let append1 string1 = string1 + ".append1"
let append2 string1 = string1 + ".append2"
let result1 = append1 <| "abc"
printfn "append1 <| \"abc\" gives %A" result1
// Reverse pipelines require parentheses.
let result2 :string = append2 <| (append1 <| "abc")
printfn "result2: %A" result2
// Reverse pipelines can be used to eliminate the need for
// parentheses in some expressions.
raise <| new System.Exception("A failure occurred.")
append1 <| "abc" gives "abc.append1" result2: "abc.append1.append2"
Platforms
Windows 7, Windows Vista SP2, Windows XP SP3, Windows XP x64 SP2, Windows Server 2008 R2, Windows Server 2008 SP2, Windows Server 2003 SP2
Version Information
F# Runtime
Supported in: 2.0, 4.0
Silverlight
Supported in: 3