Xpression class

XpressionClass.ps1

class Xpression
{
    [string]$Name
    [scriptblock]$Expression
    [hashtable] getExpression() { 
        return @{ Name = $this.Name; Expression = $this.Expression }
    }
}

class XpressionArray
{
    [Xpression[]]$Expression
    [array] Get() { 
        return $this.Expression.getExpression()
    }
    Add([string]$n, [scriptblock]$x) { 
        $temp = New-Object -TypeName Xpression
        $temp.Name = $n
        $temp.Expression = $x
        $this.Expression += $temp
    }
    Add([string]$n) { 
        $temp = New-Object -TypeName Xpression
        $temp.Name = $n
        $temp.Expression = [Scriptblock]::Create('$_.' + $n ) 
        $this.Expression += $temp
        
    }
}

# How to use it

$exp = New-Object -TypeName XpressionArray

$exp.Add('Name')
$exp.Add('Id')
$exp.Add('KB',{ $_.WorkingSet / 1Kb })
$exp.Add('MB',{ $_.WorkingSet / 1Mb })

Get-Process -Name powershell* |select $exp.Get() | Format-Table
Get-Process -Name powershell* |select $exp.Get() | Get-Member