PipeScript

0.2.8

Languages/YAML/YAML-Language.ps.ps1

Language function YAML {
<#
.SYNOPSIS
    Yaml PipeScript Language Definition.
.DESCRIPTION
    Allows PipeScript to generate Yaml.

    Because Yaml does not support comment blocks, PipeScript can be written inline inside of specialized Yaml string.

    PipeScript can be included in a multiline Yaml string with the Key PipeScript and a Value surrounded by {}
.Example
    .> {
        $yamlContent = @'
PipeScript: |
  {
    @{a='b'}
  }

List:
  - PipeScript: |
      {
        @{a='b';k2='v';k3=@{k='v'}}
      }
  - PipeScript: |
      {
        @(@{a='b'}, @{c='d'})
      }
  - PipeScript: |
      {
        @{a='b'}, @{c='d'}
      }
'@
        [OutputFile('.\HelloWorld.ps1.yaml')]$yamlContent
    }

    .> .\HelloWorld.ps1.yaml
#>
    [ValidatePattern('\.(?>yml|yaml)$')]
    param()

    $FilePattern     = '\.(?>yml|yaml)$'
    $ReplacePattern  = [Regex]::new('
        (?<Indent>\s{0,}) # Capture the indentation level
        (?<InList>-\s)? # Determine if we are in a list
        PipeScript # Then match the key Pipescript
        :\s\| # followed by a whitespace and pipe character
        (?>\r\n|\n){1,} # Match one or more newlines
        (\k<Indent>)\s{2} # The ScriptBlock must be indented at least two spaces
        (?(InList)\s{2}) # (four if it is a list)
        \{ # Then we need to match the opening brace
        (?<PipeScript> # And we finally start matching our Script
          (?:.|\s){0,}?(?= # This is zero or more characters until
              \z| # The end of the string OR
              (\k<Indent>)\s{2} # A Matching pair or quad of indentation.
              (?(InList)\s{2})
              \} # followed by a closing brace.
            )
        )
        (\k<Indent>)\s{2} # To complete the match, we check indentation once more
        (?(InList)\s{2})
        \}
        ', 'IgnorePatternWhitespace,IgnoreCase')

    # YAML is a Data Language
    $DataLanguage = $true
    $CaseSensitive = $true

    $ForeachObject = {
        begin {
            $yamlOut = [Collections.Queue]::new()
        }
        process {
            $YamlOut.Enqueue($_)
        }
        end {
            if ($yamlOut.Count -eq 1) {
                $yamlOut = $yamlOut[0]
            } else {
                $isList = $true
            }
    
            @(foreach ($yo in $yamlOut) {
                if ($yo -is [string]) {

                }
                if ($yo -is [Collections.IDictionary]) {
                    $yo = [PSCustomObject]$yo
                }
                $yamlObject = [PSCustomObject]::new($yo)
                $yamlObject.pstypenames.clear()
                $yamlObject.pstypenames.add('Yaml')
                $yamlLines  = @((Out-String -InputObject $yamlObject -Width 1kb).Trim() -split '(?>\r\n|\n)')
                $isList     = $yamlLines[0] -match '^-\s'
                $inList     = $match.Groups["InList"].Value -as [bool]
                $yamlIndent = ' ' * ($match.Groups["Indent"].Length -as [int])
                @(for ($yamlLineNumber = 0; $yamlLineNumber -lt $yamlLines.Length; $yamlLineNumber++) {
                    $yamlLine = $yamlLines[$yamlLineNumber]                    
                    $(if ($inList -and -not $isList) {
                        if (-not $yamlLineNumber) {
                            $yamlIndent + '- '
                        } else {
                            $yamlIndent + ' '
                        }
                    } else {
                        $yamlIndent
                    }) + $yamlLine
                }) -join [Environment]::NewLine
            }) -join [Environment]::Newline
        }
    }
    
}