helpers/ModulesTillPublishedonGallery/PoshRSJob/1.7.4.4/Private/GetParamVariable.ps1
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Function GetParamVariable { [CmdletBinding()] param ( [scriptblock]$ScriptBlock ) # Tokenize the script [array] $tokens = [Management.Automation.PSParser]::Tokenize($ScriptBlock, [ref]$null) | Where-Object { $_.Type -ne 'NewLine' -and $_.Type -ne 'Comment' } # old code was buggy - it can grab internal param block for code like { $a = 1; invoke-command { param($b) } -argumentlist $a } # New code know that scriptblock param() can only be the first token or right after [attribute] tokens, any other - ignored. # It also get right variable names when param($a = $b + $c, $d) and other difficult cases (see tests) $state = 0 $bracket = 0 $awaitVariable = $false foreach ($token in $tokens) { # using state machine method switch ($state) { 0 { # search for sttribute start or param if ($token.Type -eq 'Keyword' -and $token.Content -eq 'param') { $state = 3 # collect variables start $awaitVariable = $true # catch variable name after param( } elseif ($token.Type -eq 'Operator' -and $token.Content -eq '[') { #attribute start $state = 1 # check for attribute token $bracket++ } else { # no param found, break $state = -1 } } 1 { # Attribute token check. may be excessive? if ($token.Type -eq 'Attribute') { $state = 2 # wait for close attribute block } } 2 { # await attribte end if ($token.Type -eq 'Operator') { if ($token.Content -eq '[') { $bracket++ } elseif ($token.Content -eq ']') { $bracket-- if ($bracket -eq 0) { # catched attribute close bracket $state = 0 # back to param() search } } } } 3 { # inside params if ($token.Type -eq 'GroupStart' -and $token.Content -eq '(') { $bracket++ } elseif ($token.Type -eq 'GroupEnd' -and $token.Content -eq ')') { $bracket-- if ($bracket -eq 0) { # param() closed, exiting $state = -1 } } elseif ($token.Type -eq 'Operator' -and $token.Content -eq '[') { $bracket += 2 #count square brackets } elseif ($token.Type -eq 'Operator' -and $token.Content -eq ']') { $bracket -= 2 #count square brackets } elseif ($token.Type -eq 'GroupStart' -and ($token.Content -eq '{' -or $token.Content -eq '@{')) { $bracket += 2 #count curly brackets } elseif ($token.Type -eq 'GroupEnd' -and $token.Content -eq '}') { $bracket -= 2 #count curly brackets } elseif ($token.Type -eq 'Operator' -and $token.Content -eq ',' -and ($bracket -eq 1)) { $awaitVariable = $true # await variable name after comma without extra brackets } elseif ($token.Type -eq 'Variable' -and ($bracket -eq 1) -and $awaitVariable) { $awaitVariable = $false $token.Content } } } if ($state -eq -1) { break } } } |