Call　C# code snipped from PowerShell using Mono.CSharp/Roslyn

Mono.CSharp.ps1

Use-NuGetPackage Mono.CSharp -Verbose
 
#Setup Mono C# evaluater
$settings = New-Object Mono.CSharp.CompilerSettings
$printer = New-Object Mono.CSharp.ConsoleReportPrinter
$context = New-Object Mono.CSharp.CompilerContext($settings, $printer);
$evaluator = New-Object Mono.CSharp.Evaluator($context);
$evaluator.Run("using System; using System.Linq") > $null
 
#Define Func<int,int> return n^2
$func = $evaluator.Evaluate('new Func<int,int>(p => {return p * p;})')
 
#Execute func
$func.Invoke(4)

Roslyn.ps1

Use-NuGetPackage Roslyn -Verbose

#Setup Roslyn Script Engine
$scriptEngine = New-Object Roslyn.Scripting.CSharp.ScriptEngine($null, $null)
$scriptEngine.AddReference("System.Linq")
$scriptEngine.ImportNamespace("System")
$scriptEngine.ImportNamespace("System.Linq")
$session = $scriptEngine.CreateSession()

#Define Func<int,int> return n^2
$func = $session.Execute('new Func<int,int>(p => {return p * p;})')

#Execute func
$func.Invoke(4)