Languages/R/R-Language.ps.ps1
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Language function R { <# .SYNOPSIS R PipeScript Language Definition. .DESCRIPTION Allows PipeScript to generate R. Because R Scripts only allow single-line comments, this is done using a pair of comment markers. # { or # PipeScript{ begins a PipeScript block # } or # }PipeScript ends a PipeScript block ~~~r # { Uncommented lines between these two points will be ignored # # Commented lines will become PipeScript / PowerShell. # param($message = "hello world") # "puts `"$message`"" # } ~~~ .EXAMPLE Invoke-PipeScript { $rScript = ' # { Uncommented lines between these two points will be ignored # # Commented lines will become PipeScript / PowerShell. # param($message = "hello world") # "print(`"$message`")" # } ' [OutputFile('.\HelloWorld.ps1.r')]$rScript } Invoke-PipeScript .\HelloWorld.ps1.r #> [ValidatePattern('\.r$')] param() $FilePattern = '\.r$' $SingleLineCommentStart = '\#' # Any Language can be parsed with a series of regular expresssions. # For languages that only support single comments: # * The capture group IsSingleLine must be defined. # * Whitespace should not be allowed (it makes nested blocks hard to end) $startComment = "(?>(?<IsSingleLine>$SingleLineCommentStart)(?>PipeScript|PS)?\{)" $endComment = "(?>$SingleLineCommentStart(?:PipeScript)?\})" # To support templates, a language has to declare `$StartPattern` and `$EndPattern`: $StartPattern = "(?<PSStart>${startComment})" $EndPattern = "(?<PSEnd>${endComment})" # Using -LinePattern will skip any inline code not starting with # $LinePattern = "^\s{0,}\#\s{0,}" # We might have to go looking for R's interpreter $interpreter = $( # (it may just be in the path) if ($ExecutionContext.SessionState.InvokeCommand.GetCommand('RScript', 'Application')) { $ExecutionContext.SessionState.InvokeCommand.GetCommand('RScript', 'Application') } elseif ( # Or, if we're on Windows and there's a R ProgramFiles directory $IsWindows -and (Test-Path (Join-Path $env:ProgramFiles 'R')) ) { # We can look in there $ExecutionContext.SessionState.InvokeCommand.GetCommand("$( Join-Path $env:ProgramFiles 'R' | Get-ChildItem -Directory | # for the most recent version of R Sort-Object { ($_.Name -replace '^R-') -as [Version]} -Descending | Select-Object -First 1 | Join-Path -ChildPath "bin" | Join-Path -ChildPath "RScript.exe" )", "Application") } ) } |