Seq.mapi<'T,'U> Function (F#)
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Seq.mapi<'T,'U> Function (F#)


Creates a new collection whose elements are the results of applying the given function to each of the elements of the collection. The integer index passed to the function indicates the index (from 0) of element being transformed.

Namespace/Module Path: Microsoft.FSharp.Collections.Seq

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

// Signature:
Seq.mapi : (int -> 'T -> 'U) -> seq<'T> -> seq<'U>

// Usage:
Seq.mapi mapping source


Type: int -> 'T -> 'U

A function to transform items from the input sequence that also supplies the current index.


Type: seq<'T>

The input sequence.

Exception Condition




Thrown when the input sequence is null.

The result sequence.

This function is named MapIndexed in compiled assemblies. If you are accessing the function from a .NET language other than F#, or through reflection, use this name.

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

F# Core Library Versions

Supported in: 2.0, 4.0, Portable

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