Rebasing on main

Author: milseman

Sources/_MatchingEngine/Regex/DSLTree.swift

@@ -36,17 +36,17 @@ extension DSLTree {
     case stringLiteral(String)
 
     /// An embedded literal
-    case regexLiteral(AST)
+    case regexLiteral(AST.Node)
 
     // MARK: - Tree conversions
 
     /// The target of AST conversion.
     ///
     /// Keeps original AST around for rich syntatic and source information
-    case convertedRegexLiteral(Node, AST)
+    case convertedRegexLiteral(Node, AST.Node)
 
     // Fall-back for when conversion fails
-    case unconvertedRegexLiteral(AST)
+    case unconvertedRegexLiteral(AST.Node)
 
     // MARK: - Extensibility points
 
@@ -142,7 +142,7 @@ extension DSLTree.Node {
 }
 
 extension DSLTree.Node {
-  var ast: AST? {
+  var astNode: AST.Node? {
     switch self {
     case let .regexLiteral(ast):             return ast
     case let .unconvertedRegexLiteral(ast):  return ast
@@ -152,7 +152,7 @@ extension DSLTree.Node {
   }
 }
 
-extension AST {
+extension AST.Node {
   /// Converts an AST node to a `convertedRegexLiteral` node.
   var dslTreeNode: DSLTree.Node {
     func wrap(_ node: DSLTree.Node) -> DSLTree.Node {
@@ -258,6 +258,10 @@ extension AST {
         let child = v.child.dslTreeNode
         return .groupTransform(
           v.kind.value, child, transform)
+
+      case .absentFunction:
+        // TODO: What should this map to?
+        return .unconvertedRegexLiteral(self)
       }
     }
 

Sources/_MatchingEngine/Regex/Printing/PrintAsPattern.swift

@@ -43,6 +43,13 @@ extension PrettyPrinter {
     return false
   }
 
+  mutating func printBackoff(_ node: DSLTree.Node) {
+    precondition(node.astNode != nil, "unconverted node")
+    printAsCanonical(
+      .init(node.astNode!, globalOptions: nil),
+      delimiters: true)
+  }
+
   mutating func printAsPattern(_ ast: AST) {
     // TODO: Handle global options...
     let node = ast.root.dslTreeNode
@@ -58,8 +65,7 @@ extension PrettyPrinter {
     convertedFromAST node: DSLTree.Node
   ) {
     if patternBackoff(node) {
-      precondition(node.ast != nil, "unconverted node")
-      printAsCanonical(node.ast!, delimiters: true)
+      printBackoff(node)
       return
     }
 
@@ -80,6 +86,7 @@ extension PrettyPrinter {
       }
 
     case let .group(kind, child):
+      let kind = kind._patternBase
       printBlock("Group(\(kind))") { printer in
         printer.printAsPattern(convertedFromAST: child)
       }
@@ -119,10 +126,8 @@ extension PrettyPrinter {
     case let .stringLiteral(v):
       print(v._quoted)
 
-    case let .regexLiteral(v):
-      printAsCanonical(v, delimiters: true)
-    case let .unconvertedRegexLiteral(v):
-      printAsCanonical(v, delimiters: true)
+    case .regexLiteral, .unconvertedRegexLiteral:
+      printBackoff(node)
 
     case let .convertedRegexLiteral(n, _):
       // FIXME: This recursion coordinates with back-off