Getting enum values of Pseudo-Enum classes

By "Pseudo-Enum" classes I mean cases where someone's used a class with public static properties to emulate enum behaviour; e.g. as described here.

Per the example below, this is useful for classes such as [System.Management.Automation.VerbsCommon], where there is a list of values we're interested in, but no "Get All Values of This Type" method.

I wrote this function for the above type, and it works well for that, but maybe I've missed a trick / there are likely other scenarios that this code could cover which I've not thought of yet.

Clear-Host
function Get-EnumValues {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory,ValueFromPipeline)]
        [Type]$Type
    )
    process {
        if ($Type) {

            Write-Verbose ("Type: {0}" -f $Type.ToString())
            Write-Verbose ("IsEnum? {0}" -f $Type.IsEnum)

            if ($Type.IsEnum) {
                [System.Enum]::GetNames($Type)
            } else {
                #handle pseudo-enums (i.e. for cases where this trick's been used https://stackoverflow.com/a/15713789/361842)
                $Type.GetFields() | ?{$_.IsStatic -and $_.IsPublic} | select -ExpandProperty Name
            }
        } else {
            Write-Verbose ("TypeName is Null")
            $null
        }
    }
}

$t = [type][System.ConsoleColor]
Get-EnumValues $t -Verbose
$t = [type][System.Management.Automation.VerbsCommon]
Get-EnumValues $t -Verbose

Output:

VERBOSE: Type: System.ConsoleColor
VERBOSE: IsEnum? True
Black
DarkBlue
DarkGreen
DarkCyan
DarkRed
DarkMagenta
DarkYellow
Gray
DarkGray
Blue
Green
Cyan
Red
Magenta
Yellow
White
VERBOSE: Type: System.Management.Automation.VerbsCommon
VERBOSE: IsEnum? False
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I'm aware that the shorthand coding style sometimes frowned upon, such as:

`$Type.GetFields() | ?{$_.I

Let's look for scenarios that this code could cover.

Next 143296.ps1 script, using Get-Type function - Get exported types in the current session

• Exports all types from all namespaces in the current session to $allTypes, then

• Selects those with non-empty (pseudo)enumeration to auxiliary Hashtable $ppp and $subTypes.

Script 143296.ps1:

Import-Module -Name Reflection -Force
$allTypes = Get-Type -Force -Namespace * -ErrorAction SilentlyContinue
$allTypes.Count
$ppp=@{}              ### auxiliary Hashtable object, could be useful though
$allTypes | 
    ForEach-Object {
        $aux = $_ | Get-EnumValue -AsFlags
        if ( $aux.Count -ne 0 ) { $ppp.add( $_.FullName, $_.BaseType) }
    }
$ppp.Count 
$subTypes = $allTypes | Where-Object { $ppp.ContainsKey($_.FullName)}
$subTypes.Count
$subGrups = $subtypes | Group-Object -Property BaseType
$subGrups.Count
### make public the most frequent items:
$subGrups | Sort-Object -Property Count -Descending | Select-Object -First 15
                                           

Output:

PS D:\PShell> D:\PShell\CR\143296.ps1
12413
2490
2490
182

Count Name Group
----- ---- -----
1710 System.Enum {System.StringSplitOptions, System.StringComparison, System....
201 System.Object {System.String, System.EventArgs, System.BitConverter, Syste...
58 System.ValueType {System.DateTime, System.DateTimeOffset, System.Boolean, Sys...
53 System.Attribute {System.ComponentModel.BindableAttribute, System.ComponentMo...
28 System.Windows.Freezable {System.Windows.Media.Animation.ThicknessKeyFrame, System.Wi...
24 System.Windows.Framewo... {System.Windows.Shapes.Shape, System.Windows.Controls.Panel,...
22 System.Windows.Control... {Microsoft.VisualStudio.Text.Editor.OutliningMarginHeaderCon...
15 System.Windows.Media.A... {System.Windows.TextDecoration, System.Windows.Media.Animati...
11 System.Windows.Control... {System.Windows.Window, System.Windows.Controls.Primitives.B...
9 System.Windows.Depende... {System.Windows.Navigation.JournalEntry, System.Windows.Cont...
8 System.Globalization.C... {System.Globalization.GregorianCalendar, System.Globalizatio...
8 System.Windows.Control... {System.Windows.Controls.Canvas, System.Windows.Controls.Vir...
7 System.Windows.Media.P... {System.Windows.Media.ArcSegment, System.Windows.Media.Bezie...
7 System.Windows.Control... {System.Windows.Controls.Border, System.Windows.Controls.Ink...
7 System.Windows.Media.G... {System.Windows.Media.CombinedGeometry, System.Windows.Media...


The Get-EnumValue function is explained using Comment-Based Help (CBH):

`Set-StrictMode -Version latest
function Get-EnumValue {
is attributed 'FlagsAttribute' (some [Enum] types)
then output values would be hexadecimal-like strings (8+ hexadecimal ciphers);
otherwise, output values would follow type.
Applies only if -NoValues parameter evaluates to False.

.INPUTS
Valid [type], or a string for the type name.

.OUTPUTS
Always returns [OrderedDictionary] or [system.array] object (see switches).
Never outputs Null; returns an empty (.Count -eq 0) object instead.

.NOTES
If -NoValues evaluates to True, then -AsFlags is ignored.

.EXAMPLE
# Enum, flag enumeration (FlagsAttribute present on object supplied)
[System.AttributeTargets]|Get-EnumValue -AsFlags -Verbose
.EXAMPLE
# Enum, value enumeration (no FlagsAttribute on object supplied)
[System.Runtime.InteropServices.VarEnum]|Get-EnumValue -AsFlags -Verbose
.EXAMPLE
# Struct (not Enum)
[System.Double]|Get-EnumValue -Verbose
.EXAMPLE
# Class (not Enum): useful or at least interesting output
[System.Security.Claims.ClaimValueTypes]|Get-EnumValue -AsFlags | ft -a -Wrap

.REMARKS
Based on 'Get-EnumValues' function and used in answer to:
http://codereview.stackexchange.com/questions/143296/getting-enum-values-of-pseudo-enum-classes
Useful related article: 'Get-Type' - Get exported types in the current session
https://gallery.technet.microsoft.com/scriptcenter/Get-Type-Get-exported-fee19cf7

.FUNCTIONALITY
Tested: Windows 8.1/64bit, Powershell 4
#>
[CmdletBinding(PositionalBinding=$false)]
param (
[Parameter(Mandatory,ValueFromPipeline,Position=0)]$Type,
[parameter(Mandatory=$false)][Switch][bool]$NoValues,
[parameter(Mandatory=$false)][Switch][bool]$AsFlags
)
begin {

Function EnumNoEnum ([type]$noEnumClass) {
$enumFlagsHash = [ordered]@{}
$noEnumClass.GetFields() |
Where-Object {$_.IsStatic -and $_.IsPublic} |
Select-Object -Exp

StackExchange Code Review Q#143296, answer score: 2