PoshInternals

1.0

Ast.ps1

function ConvertTo-Ast
{
    [CmdletBinding()]
    param([String]$String)

    Write-Debug $String

    $Tokens = $null 
    $Errors = $null

    [System.Management.Automation.Language.Parser]::ParseInput($String, [ref]$Tokens, [ref]$Errors)

    $Errors | % { Write-Error $_ }
}

function Get-Parameter 
{
    [CmdletBinding()]
    param(
    [Parameter(Mandatory, ValueFromPipeline=$true)]
    [System.Management.Automation.Language.ScriptBlockAst]$ScriptBlock
    )

    $ParamBlock = Get-Ast -ParamBlock -Ast $ScriptBlock
    Get-Ast -Parameter -Ast $ScriptBlock
}

function Get-Ast
{
    [CmdletBinding()]
    param(
    [Parameter(Mandatory)]
    [System.Management.Automation.Language.Ast]$Ast,
    [Switch]$Attribute,
    [Switch]$ParamBlock,
    [Switch]$Parameter,
    [Switch]$TypeConstraint,
    [Switch]$First,
    [Switch]$SearchNestedBlocks,
    [ScriptBlock]$Filter
    )

    $Predicate = {
        $this = $args[0]

        Write-Verbose "$this [$($this.GetType())]"

        if ($Attribute -and $this -is ([System.Management.Automation.Language.AttributeAst]))
        {
            if ($Filter -eq $null -or $Filter.Invoke($this))
            {
                Write-Output $this    
            }
        }
        if ($ParamBlock -and $this -is ([System.Management.Automation.Language.ParamBlockAst]))
        {
            if ($Filter -eq $null -or $Filter.Invoke($this))
            {
                Write-Output $this    
            }
        }
        if ($Parameter -and $this -is ([System.Management.Automation.Language.ParameterAst]))
        {
            if ($Filter -eq $null -or $Filter.Invoke($this))
            {
                Write-Output $this    
            }
        }
        if ($TypeConstraint -and $this -is ([System.Management.Automation.Language.TypeConstraintAst]))
        {
            if ($Filter -eq $null -or $Filter.Invoke($this))
            {
                Write-Output $this    
            }
        }
    }

    if ($First)
    {
        $Ast.Find($Predicate, $SearchNestedBlocks)
    }
    else
    {
        $Ast.FindAll($Predicate, $SearchNestedBlocks)
    }
}

function Remove-Extent 
{
    [CmdletBinding()]
    param([System.Management.Automation.Language.ScriptBlockAst]$ScriptBlock,
          [System.Management.Automation.Language.IScriptExtent]$Extent)

    $ScriptBlockString = $ScriptBlock.ToString()

    Write-Verbose "Removing $($Extent.StartOffset) to $($Extent.EndOffset) in string of length $($ScriptBlockString.Length)"

    $ScriptBlockString = $ScriptBlockString.Remove($Extent.StartOffset, $Extent.EndOffset - $Extent.StartOffset)

    ConvertTo-Ast $ScriptBlockString
}