Simplified syntax doesn't recognize static members.

[mklement0]

Prerequisites

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Steps to reproduce

Note:

• If this ends up being declared to be by design, about_Simplified_Syntax should be amended to clarify that.

(Add-Type @'
public class Foo
{
  public static string Bar(string s) { return s; }
}
'@ -PassThru)::new() | ForEach-Object Bar '1'

Expected behavior

1

That is, the static .Bar() method should be called.

Actual behavior

The following error occurs:

Input name "Bar" cannot be resolved to a method.

Error details

No response

Environment data

PowerShell 7.5.0-preview.2

Visuals

No response

[jborean93]

While I agree the documentation in the about page and for the -MemberName parameter in ForEach-Object could be expanded to state this won't work for static methods it does look to be by design. You can't call static methods as a normal member and Get-Member doesn't even show it unless you explicitly opt into to showing static members of that type with Get-Member -Static.

Add-Type @'
public class Foo
{
  public static string Bar(string s) { return s; }
}
'@

$f = [Foo]::new()
$f.Bar('a')  # Doesn't work
$f | Get-Member # Doesn't show Bar

$f | Get-Member -Static  # Does show Bar

[mklement0]

@jborean93:

• It's true that when it comes to direct method calls there's a necessary distinction - driven by syntax requirements - between instance member access (.) and static member access (::), and it is true that this distinction is also reflected in the logic of Get-Member, which reports only instance members by default, and requires -Static to alternatively report static members.

• By contrast, with simplified syntax there is no requirement to syntactically distinguish between accessing instance and
  static members.

Therefore, there are two possible resolutions:

• Preferably (to me): Extend simplified syntax to also support accessing static members.

• Officially declare the current behavior to be by design, and amend the docs accordingly.

[jborean93]

Personally it makes sense for ForEach-Object to run on multiple instances in an array but not for a static method. Why would you be enumerating multiple instances to call a static method that has no correlation to that instance itself. While I don't know what the implementation of this is it sounds like it could add more overhead as now it needs to query both the ETS members and then the members on the type itself which isn't part of the object but the .NET type itself.

Ultimately a question for the WG.

[mklement0]

You're right:

I've been trying to come with real-world examples of when static member access may be useful with simplified syntax, and so far the only - not very compelling - examples I've come up with are the following:

# Possibly should be the same as:
#   [regex] 'foo' | % { $_.GetType()::CacheSize }
[regex] 'foo' | % CacheSize

# Possibly should be the same as:
#   [regex] 'foo' | % { $_.GetType()::unescape('a\\b') }
[regex] 'foo' | % Unescape 'a\\b'

To put it differently: the suggested ability to access static members would only be useful for static properties and for static methods whose parameters are (by definition) unrelated to the specific properties of each input instance.

Therefore - unless someone finds additional angles - I agree that amending the docs is sufficient.

[rhubarb-geek-nz]

While not using the simplified syntax it could be done with with reflection.

(Add-Type @'
public class Foo
{
  public static string Bar(string s) { return s; }
}
'@ -PassThru)::new() | ForEach-Object { $_.GetType().GetMethod('Bar',[System.Reflection.BindingFlags]'Static, Public').Invoke($null,[string[]](,'1')) }

[mklement0]

@rhubarb-geek-nz: no need for reflection: :: also works on expressions:

(Add-Type @'
public class Foo
{
  public static string Bar(string s) { return s; }
}
'@ -PassThru)::new() | 
  ForEach-Object { $_.GetType()::Bar('1') }

[SeeminglyScience]

Even just $_::Bar('1') will work there FYI

[mklement0]

I appreciate all the feedback.

I've concluded that adding a note to the docs is sufficient, so I'm closing this.

See:

• Clarify that the -MemberName / -Property parameters can only access instance members, not also static ones MicrosoftDocs/PowerShell-Docs#11047
• Clarify the implied parameter names when using simplified syntax positionally MicrosoftDocs/PowerShell-Docs#11048

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