Add some conventient methods to RawTokenKind

Sources/SwiftSyntax/SyntaxArena.swift

@@ -143,7 +143,8 @@ public class SyntaxArena {
   ///
   /// "managed" means it's empty, a part of "source buffer", or in the memory
   /// allocated by the underlying arena.
-  func contains(text: SyntaxText) -> Bool {
+  @_spi(RawSyntax)
+  public func contains(text: SyntaxText) -> Bool {
     return (text.isEmpty ||
             sourceBufferContains(text.baseAddress!) ||
             allocator.contains(address: text.baseAddress!))

Sources/SwiftSyntax/TokenKind.swift.gyb

@@ -166,6 +166,64 @@ public enum RawTokenKind {
 %   if token.text:
     case .${token.swift_kind()}: return "${token.text}"
 %   end
+% end
+    default: return nil
+    }
+  }
+
+  /// Returns `true` if the token is a Swift keyword.
+  ///
+  /// Keywords are reserved unconditionally for use by Swift and may not
+  /// appear as identifiers in any position without being escaped. For example,
+  /// `class`, `func`, or `import`.
+  public var isKeyword: Bool {
+    switch self {
+    case .eof: return false
+% for token in SYNTAX_TOKENS:
+%   if token.is_keyword:
+    case .${token.swift_kind()}: return true
+%   else:
+    case .${token.swift_kind()}: return false
+%   end
+% end
+    }
+  }
+
+  /// Returns `true` if the token is a Swift punctuator.
+  ///
+  /// Punctuation tokens generally separate identifiers from each other. For
+  /// example, the '<' and '>' characters in a generic parameter list, or the
+  /// quote characters in a string literal.
+  public var isPunctuation: Bool {
+    switch self {
+    case .eof: return false
+% for token in SYNTAX_TOKENS:
+%   if type(token).__name__ == 'Punctuator':
+    case .${token.swift_kind()}: return true
+%   else:
+    case .${token.swift_kind()}: return false
+%   end
+% end
+    }
+  }
+
+  @_spi(RawSyntax)
+  public init?(keyword text: SyntaxText) {
+%{
+tokens_by_length = {}
+for token in SYNTAX_TOKENS:
+  if token.is_keyword:
+    tokens_by_length.setdefault(len(token.text), []).append(token)
+}%
+    switch text.count {
+% for len, tokens in sorted(tokens_by_length.items()):
+    case ${len}:
+      switch text {
+%   for token in tokens:
+      case "${token.text}": self = .${token.swift_kind()}
+%   end
+      default: return nil
+      }
 % end
     default: return nil
     }

Sources/SwiftSyntax/Trivia.swift.gyb

@@ -236,7 +236,7 @@ extension TriviaPiece {
 /// In contrast to `TriviaPiece`, a `RawTriviaPiece` does not own the source
 /// text of a the trivia.
 @_spi(RawSyntax)
-public enum RawTriviaPiece {
+public enum RawTriviaPiece: Equatable {
 % for trivia in TRIVIAS:
 %   if trivia.is_collection():
   case ${trivia.lower_name}s(Int)
@@ -329,3 +329,17 @@ extension RawTriviaPiece {
     }
   }
 }
+
+extension RawTriviaPiece {
+  /// Returns true if the trivia is `.newlines`, `.carriageReturns` or `.carriageReturnLineFeeds`
+  public var isNewline: Bool {
+    switch self {
+    case .newlines,
+         .carriageReturns,
+         .carriageReturnLineFeeds:
+      return true
+    default:
+      return false
+    }
+  }
+}