Fix retain cycles in the Swift runtime

runtime-testsuite/resources/org/antlr/v4/test/runtime/templates/Swift.test.stg

@@ -72,7 +72,7 @@ TokenStartColumnEquals(i) ::= <%self._tokenStartCharPositionInLine == <i>%>
 
 ImportListener(X) ::= ""
 
-GetExpectedTokenNames() ::= "try self.getExpectedTokens().toString(self.tokenNames)"
+GetExpectedTokenNames() ::= "try self.getExpectedTokens().toString(self.getVocabulary())"
 
 RuleInvocationStack() ::= "getRuleInvocationStack().description.replacingOccurrences(of: \"\\\"\", with: \"\")"
 

runtime/Swift/Sources/Antlr4/BailErrorStrategy.swift

@@ -41,13 +41,13 @@ public class BailErrorStrategy: DefaultErrorStrategy {
     /// original _org.antlr.v4.runtime.RecognitionException_.
     /// 
     override public func recover(_ recognizer: Parser, _ e: AnyObject) throws {
-        var context: ParserRuleContext? = recognizer.getContext()
-        while let contextWrap = context{
+        var context = recognizer.getContext()
+        while let contextWrap = context {
             contextWrap.exception = e
             context = (contextWrap.getParent() as? ParserRuleContext)
         }
 
-        throw  ANTLRException.recognition(e: e)
+        throw ANTLRException.recognition(e: e)
     }
 
     /// 
@@ -56,15 +56,14 @@ public class BailErrorStrategy: DefaultErrorStrategy {
     /// 
     override
     public func recoverInline(_ recognizer: Parser) throws -> Token {
-        let e: InputMismatchException = try InputMismatchException(recognizer)
-        var context: ParserRuleContext? = recognizer.getContext()
+        let e = try InputMismatchException(recognizer)
+        var context = recognizer.getContext()
         while let contextWrap = context {
              contextWrap.exception = e
              context = (contextWrap.getParent() as? ParserRuleContext)
         }
 
-        throw  ANTLRException.recognition(e: e)
-
+        throw ANTLRException.recognition(e: e)
     }
 
     /// 

runtime/Swift/Sources/Antlr4/BufferedTokenStream.swift

@@ -176,7 +176,7 @@ public class BufferedTokenStream: TokenStream {
             let  index = tokens.count - 1
             throw ANTLRError.indexOutOfBounds(msg: "token index  \(i) out of range 0..\(index)")
         }
-        return tokens[i] //tokens[i]
+        return tokens[i]
     }
 
     /// 
@@ -202,7 +202,6 @@ public class BufferedTokenStream: TokenStream {
         return subset
     }
 
-    //TODO: LT(i)!.getType();
     public func LA(_ i: Int) throws -> Int {
         return try LT(i)!.getType()
     }
@@ -273,11 +272,11 @@ public class BufferedTokenStream: TokenStream {
         fetchedEOF = false
     }
 
-    public func getTokens() -> Array<Token> {
+    public func getTokens() -> [Token] {
         return tokens
     }
 
-    public func getTokens(_ start: Int, _ stop: Int) throws -> Array<Token>? {
+    public func getTokens(_ start: Int, _ stop: Int) throws -> [Token]? {
         return try getTokens(start, stop, nil)
     }
 
@@ -286,40 +285,36 @@ public class BufferedTokenStream: TokenStream {
     /// the token type BitSet.  Return null if no tokens were found.  This
     /// method looks at both on and off channel tokens.
     /// 
-    public func getTokens(_ start: Int, _ stop: Int, _ types: Set<Int>?) throws -> Array<Token>? {
+    public func getTokens(_ start: Int, _ stop: Int, _ types: Set<Int>?) throws -> [Token]? {
         try lazyInit()
-        if start < 0 || stop >= tokens.count ||
-                stop < 0 || start >= tokens.count {
-            throw ANTLRError.indexOutOfBounds(msg: "start \(start) or stop \(stop) not in 0..\(tokens.count - 1)")
+        if start < 0 || start >= tokens.count ||
+            stop < 0 || stop >= tokens.count {
+            throw ANTLRError.indexOutOfBounds(msg: "start \(start) or stop \(stop) not in 0...\(tokens.count - 1)")
 
         }
         if start > stop {
             return nil
         }
 
-
-        var filteredTokens: Array<Token> = Array<Token>()
+        var filteredTokens = [Token]()
         for i in start...stop {
-            let t: Token = tokens[i]
-            if let types = types , !types.contains(t.getType()) {
-            }else {
+            let t = tokens[i]
+            if let types = types, !types.contains(t.getType()) {
+            }
+            else {
                 filteredTokens.append(t)
             }
-
         }
         if filteredTokens.isEmpty {
             return nil
-            //filteredTokens = nil;
         }
         return filteredTokens
     }
 
-    public func getTokens(_ start: Int, _ stop: Int, _ ttype: Int) throws -> Array<Token>? {
-        //TODO Set<Int> initialCapacity
-        var s: Set<Int> = Set<Int>()
+    public func getTokens(_ start: Int, _ stop: Int, _ ttype: Int) throws -> [Token]? {
+        var s = Set<Int>()
         s.insert(ttype)
-        //s.append(ttype);
-        return try  getTokens(start, stop, s)
+        return try getTokens(start, stop, s)
     }
 
     /// 
@@ -464,7 +459,7 @@ public class BufferedTokenStream: TokenStream {
                 }
             }
         }
-        if hidden.count == 0 {
+        if hidden.isEmpty {
             return nil
         }
         return hidden

runtime/Swift/Sources/Antlr4/CharStream.swift

@@ -25,5 +25,5 @@ public protocol CharStream: IntStream {
     /// - throws: _ANTLRError.unsupportedOperation_ if the stream does not support
     /// getting the text of the specified interval
     /// 
-    func getText(_ interval: Interval) -> String
+    func getText(_ interval: Interval) throws -> String
 }

runtime/Swift/Sources/Antlr4/CommonToken.swift

@@ -7,12 +7,6 @@
 
 
 public class CommonToken: WritableToken {
-    /// 
-    /// An empty _org.antlr.v4.runtime.misc.Pair_ which is used as the default value of
-    /// _#source_ for tokens that do not have a source.
-    /// 
-    internal static let EMPTY_SOURCE: (TokenSource?, CharStream?) = (nil, nil)
-
     /// 
     /// This is the backing field for _#getType_ and _#setType_.
     /// 
@@ -21,20 +15,20 @@ public class CommonToken: WritableToken {
     /// 
     /// This is the backing field for _#getLine_ and _#setLine_.
     /// 
-    internal var line: Int = 0
+    internal var line = 0
 
     /// 
     /// This is the backing field for _#getCharPositionInLine_ and
     /// _#setCharPositionInLine_.
     /// 
-    internal var charPositionInLine: Int = -1
+    internal var charPositionInLine = -1
     // set to invalid position
 
     /// 
     /// This is the backing field for _#getChannel_ and
     /// _#setChannel_.
     /// 
-    internal var channel: Int = DEFAULT_CHANNEL
+    internal var channel = DEFAULT_CHANNEL
 
     /// 
     /// This is the backing field for _#getTokenSource_ and
@@ -47,7 +41,7 @@ public class CommonToken: WritableToken {
     /// _org.antlr.v4.runtime.misc.Pair_ containing these values.
     /// 
 
-    internal var source: (TokenSource?, CharStream?)
+    internal let source: TokenSourceAndStream
 
     /// 
     /// This is the backing field for _#getText_ when the token text is
@@ -61,19 +55,19 @@ public class CommonToken: WritableToken {
     /// This is the backing field for _#getTokenIndex_ and
     /// _#setTokenIndex_.
     /// 
-    internal var index: Int = -1
+    internal var index = -1
 
     /// 
     /// This is the backing field for _#getStartIndex_ and
     /// _#setStartIndex_.
     /// 
-    internal var start: Int = 0
+    internal var start = 0
 
     /// 
     /// This is the backing field for _#getStopIndex_ and
     /// _#setStopIndex_.
     /// 
-    internal var stop: Int = 0
+    internal var stop = 0
 
     /// 
     /// Constructs a new _org.antlr.v4.runtime.CommonToken_ with the specified token type.
@@ -85,16 +79,16 @@ public class CommonToken: WritableToken {
 
     public init(_ type: Int) {
         self.type = type
-        self.source = CommonToken.EMPTY_SOURCE
+        self.source = TokenSourceAndStream.EMPTY
     }
 
-    public init(_ source: (TokenSource?, CharStream?), _ type: Int, _ channel: Int, _ start: Int, _ stop: Int) {
+    public init(_ source: TokenSourceAndStream, _ type: Int, _ channel: Int, _ start: Int, _ stop: Int) {
         self.source = source
         self.type = type
         self.channel = channel
         self.start = start
         self.stop = stop
-        if let tsource = source.0 {
+        if let tsource = source.tokenSource {
             self.line = tsource.getLine()
             self.charPositionInLine = tsource.getCharPositionInLine()
         }
@@ -111,20 +105,12 @@ public class CommonToken: WritableToken {
         self.type = type
         self.channel = CommonToken.DEFAULT_CHANNEL
         self.text = text
-        self.source = CommonToken.EMPTY_SOURCE
+        self.source = TokenSourceAndStream.EMPTY
     }
 
     /// 
     /// Constructs a new _org.antlr.v4.runtime.CommonToken_ as a copy of another _org.antlr.v4.runtime.Token_.
-    /// 
-    /// 
-    /// If `oldToken` is also a _org.antlr.v4.runtime.CommonToken_ instance, the newly
-    /// constructed token will share a reference to the _#text_ field and
-    /// the _org.antlr.v4.runtime.misc.Pair_ stored in _#source_. Otherwise, _#text_ will
-    /// be assigned the result of calling _#getText_, and _#source_
-    /// will be constructed from the result of _org.antlr.v4.runtime.Token#getTokenSource_ and
-    /// _org.antlr.v4.runtime.Token#getInputStream_.
-    /// 
+    ///
     /// - parameter oldToken: The token to copy.
     /// 
     public init(_ oldToken: Token) {
@@ -135,14 +121,8 @@ public class CommonToken: WritableToken {
         channel = oldToken.getChannel()
         start = oldToken.getStartIndex()
         stop = oldToken.getStopIndex()
-
-        if oldToken is CommonToken {
-            text = (oldToken as! CommonToken).text
-            source = (oldToken as! CommonToken).source
-        } else {
-            text = oldToken.getText()
-            source = (oldToken.getTokenSource(), oldToken.getInputStream())
-        }
+        text = oldToken.getText()
+        source = oldToken.getTokenSourceAndStream()
     }
 
 
@@ -157,14 +137,19 @@ public class CommonToken: WritableToken {
 
 
     public func getText() -> String? {
-        if text != nil {
-            return text!
+        if let text = text {
+            return text
         }
 
         if let input = getInputStream() {
-            let n: Int = input.size()
+            let n = input.size()
             if start < n && stop < n {
-                return input.getText(Interval.of(start, stop))
+                do {
+                    return try input.getText(Interval.of(start, stop))
+                }
+                catch {
+                    return nil
+                }
             } else {
                 return "<EOF>"
             }
@@ -247,23 +232,25 @@ public class CommonToken: WritableToken {
 
 
     public func getTokenSource() -> TokenSource? {
-        return source.0
+        return source.tokenSource
     }
 
 
     public func getInputStream() -> CharStream? {
-        return source.1
+        return source.stream
+    }
+
+    public func getTokenSourceAndStream() -> TokenSourceAndStream {
+        return source
     }
 
     public var description: String {
         return toString(nil)
     }
 
     public func toString(_ r: Recognizer<ATNSimulator>?) -> String {
-        var channelStr: String = ""
-        if channel > 0 {
-            channelStr = ",channel=\(channel)"
-        }
+        let channelStr = (channel > 0 ? ",channel=\(channel)" : "")
+
         var txt: String
         if let tokenText = getText() {
             txt = tokenText.replacingOccurrences(of: "\n", with: "\\n")
@@ -272,12 +259,16 @@ public class CommonToken: WritableToken {
         } else {
             txt = "<no text>"
         }
-        var typeString = "\(type)"
+        let typeString: String
         if let r = r {
-            typeString = r.getVocabulary().getDisplayName(type);
+            typeString = r.getVocabulary().getDisplayName(type)
+        }
+        else {
+            typeString = "\(type)"
         }
        return "[@\(getTokenIndex()),\(start):\(stop)='\(txt)',<\(typeString)>\(channelStr),\(line):\(getCharPositionInLine())]"
     }
+
     public var visited: Bool {
         get {
             return _visited

runtime/Swift/Sources/Antlr4/CommonTokenFactory.swift

@@ -65,18 +65,17 @@ public class CommonTokenFactory: TokenFactory {
     }
 
 
-    public func create(_ source: (TokenSource?, CharStream?), _ type: Int, _ text: String?,
+    public func create(_ source: TokenSourceAndStream, _ type: Int, _ text: String?,
                        _ channel: Int, _ start: Int, _ stop: Int,
                        _ line: Int, _ charPositionInLine: Int) -> Token {
-        let t: CommonToken = CommonToken(source, type, channel, start, stop)
+        let t = CommonToken(source, type, channel, start, stop)
         t.setLine(line)
         t.setCharPositionInLine(charPositionInLine)
-        if text != nil {
-            t.setText(text!)
-        } else {
-            if let cStream = source.1 , copyText {
-                t.setText(cStream.getText(Interval.of(start, stop)))
-            }
+        if let text = text {
+            t.setText(text)
+        }
+        else if let cStream = source.stream, copyText {
+            t.setText(try! cStream.getText(Interval.of(start, stop)))
         }
 
         return t