feat: Move-Turtle ( Fixes #51 )

Author: James Brundage

Commands/Move-Turtle.ps1

@@ -0,0 +1,70 @@
+function Move-Turtle {
+    <#
+    .SYNOPSIS
+        Moves a turtle.
+    .DESCRIPTION
+        Moves a turtle by invoking a method with any number of arguments.
+    .EXAMPLE
+        New-Turtle | 
+            Move-Turtle Forward 10 |
+            Move-Turtle Right 90 |
+            Move-Turtle Forward 10 |
+            Move-Turtle Right 90 |
+            Move-Turtle Forward 10 |
+            Move-Turtle Right 90 |
+            Move-Turtle Forward 10 |
+            Move-Turtle Right 90 |
+            Save-Turtle "./Square.svg"
+    #>
+    [CmdletBinding(PositionalBinding=$false)]
+    param(
+    # The method used to move the turtle.
+    # Any method on the turtle can be called this way.
+    [Parameter(Position=1,ValueFromPipelineByPropertyName)]
+    [ArgumentCompleter({
+        param ( $commandName, $parameterName, $wordToComplete, $commandAst, $fakeBoundParameters )
+        if (-not $script:TurtleTypeData) {
+            $script:TurtleTypeData = Get-TypeData -TypeName Turtle
+        } 
+        $methodNames = @(foreach ($memberName in $script:TurtleTypeData.Members.Keys) {
+            if ($script:TurtleTypeData.Members[$memberName] -is
+                [Management.Automation.Runspaces.ScriptMethodData]) {
+                $memberName
+            }
+        })
+                
+        if ($wordToComplete) {
+            return $methodNames -like "$wordToComplete*"
+        } else {
+            return $methodNames
+        }
+    })]
+    [string]
+    $Method = 'Forward',
+
+    # The arguments to pass to the method.
+    [Parameter(ValueFromRemainingArguments,ValueFromPipelineByPropertyName)]
+    [PSObject[]]
+    $ArgumentList = 1,
+
+    # The turtle input object.
+    # If not provided, a new turtle will be created.
+    [Parameter(ValueFromPipeline)]
+    [PSObject]
+    $InputObject
+    )
+
+    process {
+        if (-not $PSBoundParameters.InputObject) {            
+            $InputObject = $PSBoundParameters['InputObject'] = [PSCustomObject]@{PSTypeName='Turtle'}            
+        }        
+        
+        $inputMethod = $inputObject.psobject.Methods[$method]
+        if (-not $inputMethod) {
+            Write-Error "Method '$method' not found on Turtle object."
+            return
+        }
+
+        $inputMethod.Invoke($ArgumentList)
+    }
+}