Overhaul quantification optimizations

Sources/_StringProcessing/ConsumerInterface.swift

@@ -391,9 +391,8 @@ extension DSLTree.CustomCharacterClass.Member {
 
       return { input, bounds in
         let curIdx = bounds.lowerBound
-        let nextIndex = isCharacterSemantic
-          ? input.index(after: curIdx)
-          : input.unicodeScalars.index(after: curIdx)
+        let nextIndex = input.index(
+          after: curIdx, isScalarSemantics: !isCharacterSemantic)
 
         // Under grapheme semantics, we compare based on single NFC scalars. If
         // such a character is not single scalar under NFC, the match fails. In
@@ -603,9 +602,9 @@ extension AST.Atom.CharacterProperty {
         if p(input, bounds) != nil { return nil }
 
         // TODO: bounds check
-        return opts.semanticLevel == .graphemeCluster
-          ? input.index(after: bounds.lowerBound)
-          : input.unicodeScalars.index(after: bounds.lowerBound)
+        return input.index(
+          after: bounds.lowerBound, 
+          isScalarSemantics: opts.semanticLevel == .unicodeScalar)
       }
     }
 

Sources/_StringProcessing/Engine/InstPayload.swift

@@ -381,7 +381,7 @@ struct QuantifyPayload: RawRepresentable {
     case asciiBitset = 0
     case asciiChar = 1
     case any = 2
-    case builtin = 4
+    case builtinCC = 4
   }
 
   // TODO: figure out how to better organize this...
@@ -408,6 +408,14 @@ struct QuantifyPayload: RawRepresentable {
   var typeMask: UInt64       { 7 }
   var payloadMask: UInt64    { 0xFF_FF }
 
+  // Calculate the maximum number of trips, else UInt64.max if unbounded
+  var maxTrips: UInt64 {
+    guard let maxExtraTrips else {
+      return UInt64.max
+    }
+    return minTrips + maxExtraTrips
+  }
+
   static func packInfoValues(
     _ kind: AST.Quantification.Kind,
     _ minTrips: Int,
@@ -485,7 +493,7 @@ struct QuantifyPayload: RawRepresentable {
       + (model.isInverted ? 1 << 9 : 0)
       + (model.isStrictASCII ? 1 << 10 : 0)
     self.rawValue = packedModel
-      + QuantifyPayload.packInfoValues(kind, minTrips, maxExtraTrips, .builtin, isScalarSemantics: isScalarSemantics)
+      + QuantifyPayload.packInfoValues(kind, minTrips, maxExtraTrips, .builtinCC, isScalarSemantics: isScalarSemantics)
   }
 
   var type: PayloadType {
@@ -531,7 +539,7 @@ struct QuantifyPayload: RawRepresentable {
     (self.rawValue & 1) == 1
   }
 
-  var builtin: _CharacterClassModel.Representation {
+  var builtinCC: _CharacterClassModel.Representation {
     _CharacterClassModel.Representation(rawValue: self.rawValue & 0xFF)!
   }
   var builtinIsInverted: Bool {

Sources/_StringProcessing/Engine/MEBuiltins.swift

@@ -223,6 +223,25 @@ extension String {
     else { return nil }
     return next
   }
+
+  internal func matchRegexDot(
+    at currentPosition: Index,
+    limitedBy end: Index,
+    anyMatchesNewline: Bool,
+    isScalarSemantics: Bool
+  ) -> Index? {
+    guard currentPosition < end else { return nil }
+
+    if anyMatchesNewline {
+      return index(
+        after: currentPosition, isScalarSemantics: isScalarSemantics)
+    }
+
+    return matchAnyNonNewline(
+      at: currentPosition,
+      limitedBy: end,
+      isScalarSemantics: isScalarSemantics)
+  }
 }
 
 // MARK: - Built-in character class matching