Seq.truncate<'T> Function (F#)
Returns a sequence that when enumerated returns at most N elements.
Namespace/Module Path: Microsoft.FSharp.Collections.Seq
Assembly: FSharp.Core (in FSharp.Core.dll)
// Signature:
Seq.truncate : int -> seq<'T> -> seq<'T>
// Usage:
Seq.truncate count source
Parameters
Exceptions
Exception |
Condition |
|---|---|
Thrown when the input sequence is null. |
Return Value
The result sequence.
Remarks
This function is named Truncate in compiled assemblies. If you are accessing the function from a language other than F#, or through reflection, use this name.
Example
The following example demonstrates the use of Seq.truncate and contrasts the behavior with Seq.take.
let mySeq = seq { for i in 1 .. 10 -> i*i }
let truncatedSeq = Seq.truncate 5 mySeq
let takenSeq = Seq.take 5 mySeq
let truncatedSeq2 = Seq.truncate 20 mySeq
let takenSeq2 = Seq.take 20 mySeq
let printSeq seq1 = Seq.iter (printf "%A ") seq1; printfn ""
// Up to this point, the sequences are not evaluated.
// The following code causes the sequences to be evaluated.
truncatedSeq |> printSeq
truncatedSeq2 |> printSeq
takenSeq |> printSeq
// The following line produces a run-time error (in printSeq):
takenSeq2 |> printSeq
1 4 9 16 25 1 4 9 16 25 36 49 64 81 100 1 4 9 16 25 1 4 9 16 25 36 49 64 81 100
Platforms
Windows 8, Windows 7, Windows Server 2012, Windows Server 2008 R2
Version Information
F# Core Library Versions
Supported in: 2.0, 4.0, Portable