Mastering Windows PowerShell Scripting - Third Edition

AST

The AST in PowerShell is available for any script block; an example is as follows:

{ Write-Host 'content' }.Ast 

The script block that defines a function can be retrieved via Get-Command:

function Write-Content { Write-Host 'content' } 
(Get-Command Write-Content).ScriptBlock 

Or, the script block defining a function can be retrieved using Get-Item:

function Write-Content { Write-Host 'content' }(Get-Item function:\Write-Content).ScriptBlock 

It is possible to work down through the content of the script block using AST. For example, the first argument for the Write-Host command might be accessed, as follows:

{ Write-Host 'content' }.Ast. 
                         Endblock. 
                         Statements. 
                         PipelineElements. 
                         CommandElements[1] 

The preceding approach is rough, and simply ...