Adding support for Pipescript inline in YAML (#147)

Author: James Brundage

Transpilers/Inline/Inline.YAML.psx.ps1

@@ -0,0 +1,138 @@
+<#
+.SYNOPSIS
+    Yaml File Transpiler.
+.DESCRIPTION
+    Transpiles Yaml with Inline PipeScript into 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
+#>
+[ValidateScript({
+    $cmdInfo = $_
+    if ($cmdInfo.Source -match '\.(?>yml|yaml)$') {
+        return $true
+    }
+    return $false
+})]
+param(
+# The command information.  This will include the path to the file.
+[Parameter(Mandatory,ValueFromPipeline)]
+$CommandInfo,
+
+# A dictionary of parameters.
+[Collections.IDictionary]
+$Parameter,
+
+# A list of arguments.
+[PSObject[]]
+$ArgumentList
+)
+
+begin {
+    # We start off by declaring a number of regular expressions:    
+    
+    # Create a splat containing arguments to the core inline transpiler
+    $Splat      = [Ordered]@{
+        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')
+    }
+}
+
+process {
+    # Add parameters related to the file
+    $Splat.SourceFile = $commandInfo.Source -as [IO.FileInfo]
+    $Splat.SourceText = [IO.File]::ReadAllText($commandInfo.Source)
+    if ($Parameter) { $splat.Parameter = $Parameter }
+    if ($ArgumentList) { $splat.ArgumentList = $ArgumentList }
+    $Splat.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
+        }
+    }
+    # Call the core inline transpiler.
+    .>PipeScript.Inline @Splat
+}