How does Select-Object stop the pipeline in PowerShell v3?

Question

In PowerShell v2, the following line:

1..3| foreach { Write-Host \"Value : $_\"; $_ }| select -First 1

Would display:

Value         


        

Answer 1

I know that throwing a PipelineStoppedException stops the pipeline. The following example will simulate what you see with Select -first 1 in v3.0, in v2.0:

filter Select-Improved($first) {
    begin{
        $count = 0
    }
    process{
        $_
        $count++
        if($count -ge $first){throw (new-object System.Management.Automation.PipelineStoppedException)}
    }
}

trap{continue}
1..3| foreach { Write-Host "Value : $_"; $_ }| Select-Improved -first 1
write-host "after"