Patterns.Let Active Pattern (F#)

  • Article

Recognizes expressions that represent let bindings.

Namespace/Module Path: Microsoft.FSharp.Quotations.Patterns

Assembly: FSharp.Core (in FSharp.Core.dll)

// Signature:
( |Let|_| ) : (input:Expr) -> (Var * Expr * Expr) option

Parameters

  • input
    Type: Expr

    The input expression to match against.

Return Value

The formal return type is (Var * Expr * Expr) option. The option indicates whether the input results in a match. In a pattern matching expression, the input is decomposed, upon a successful match, into a tuple of three elements. The first element is a Var object that represents the value that is being defined. The second element represents the body of the let expression. The third element represents the expression that follows the let binding, or, in the verbose syntax, the expression that follows the in keyword.

Remarks

This function is named LetPattern in the .NET Framework assembly. If you are accessing the member from a .NET Framework language other than F#, or through reflection, use this name.

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

See Also

Reference

Quotations.Patterns Module (F#)

Microsoft.FSharp.Quotations Namespace (F#)