Control statements in assignment RHS #231

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1. michaelblyons

   added

   syntax

   on Jun 23, 2026
2. michaelblyons commented on Jun 23, 2026

   

   michaelblyons

   on Jun 23, 2026

   Last edited by michaelblyons

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   Hi Steve, thanks for reporting!

   Do you know if those conditionals, loops, and exceptions are available in any arbitrary expression?

   Like can I do this with a try/catch?

   if (2 * try { Get-Thing } catch { 4 } -gt $sentinel )
   { echo Foo }
3. michaelblyons commented on Jun 23, 2026

   

   michaelblyons

   on Jun 23, 2026

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   The OP's pattern for if is seen in the official docs in Assignment Operators:

   You can also assign the value created by a statement to a variable, as in the following example:

   $a = if ($b -lt 0) { 0 } else { $b }

   This example assigns zero to the $a variable if the value of $b is less than zero. It assigns the value of $b to $a if the value of $b isn't less than zero.

   And as an example, not itself documented at foreach:

         $filesToProcess = if ($_ -is [System.IO.FileSystemInfo]) {
           $_
         } else {
           Get-Item -Path $Path
         }
4. michaelblyons commented on Jun 23, 2026

   

   michaelblyons

   on Jun 23, 2026

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   I think I've found the real documentation for this at Statement values. These can get crazy:

   $i = 1
   $v = while ($i -le 5) {
       $i                   # $i is written to the pipeline
       if ($i -band 1) {
           "odd"            # conditionally written to the pipeline
       }
       ++$i                 # not written to the pipeline
   }
   # $v is object[], Length 8, value 1,"odd",2,3,"odd",4,5,"odd"

   Does this mean that technically every statement is an expression? Including function and class definitions?
5. michaelblyons commented on Jun 23, 2026

   

   michaelblyons

   on Jun 23, 2026

   Last edited by michaelblyons

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   As usual, PowerShell is more complicated.

   # legal, $foo is 4 (= 0 + 4)
   $foo =     try { Get-Thing } catch { 0 } + 4
   
   # crashes
   $foo = 4 + try { Get-Thing } catch { 0 }
   
   # compiles, but unclear what $foo becomes
   $foo = function Name { 5; Write-Host 6; return 7 }

   I think we move exceptions, loops, flow, and conditionals from statements to expressions-without-commands and let the user sort it out if they try to add 4 + try {....
6. michaelblyons

   added a commit that references this issue on Jun 23, 2026

   Support statement values

   ...

   54f5f25
7. michaelblyons

   linked a pull request that will close this issueSupport statement values #233on Jun 23, 2026
8. michaelblyons

   added a commit that references this issue on Jun 24, 2026

   Support statement values (#233)

   ...

   d8c3c5d
9. michaelblyons

   closed this as completedin #233on Jun 24, 2026
10. michaelblyons

    added a commit that references this issue on Jun 24, 2026

    Support statement values (#233)

    ...

    45b7abf