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Patterns.NewUnionCase Active Pattern (F#)

Den Delimarsky|Last Updated: 8/18/2017
1 Contributor

Recognizes expressions that represent the construction of particular union case values.

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

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


// Signature:
( |NewUnionCase|_| ) : (input:Expr} -> (UnionCaseInfo * Expr list) option


input Type: Expr

The input expression to match against.

Return Value

The formal return type is (UnionCaseInfo * Expr list) option. The option type indicates whether the input results a successful match. In a pattern matching expression, the input is decomposed (upon a successful match) into a tuple of two elements. The first element is a UnionCaseInfo object that represents the case of a discriminated union, and the second element is an expression list that represents the arguments.


This function is named NewUnionCasePattern 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.


Windows 8, Windows 7, Windows Server 2012, Windows Server 2008 R2

Version Information

F# Core Library Versions

Supported in: 2.0, 4.0, Portable

See Also

Quotations.Patterns Module (F#)

Microsoft.FSharp.Quotations Namespace (F#)

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