Cleanup the ParseTree hierarchy and open its functions

antlr-kotlin-benchmarks/src/commonMain/kotlin/org/antlr/v4/kotlinruntime/benchmarks/mysql/MySQLErrorListener.kt

@@ -106,8 +106,8 @@ public class MySQLErrorListener : BaseErrorListener() {
       // Walk up from generic rules to reach something that gives us more context, if needed.
       var context = parser.context
 
-      while (context?.parent != null && simpleRules.contains(context.ruleIndex)) {
-        context = context.parent as ParserRuleContext?
+      while (context?.getParent() != null && simpleRules.contains(context.ruleIndex)) {
+        context = context.getParent()
       }
 
       // Try to find the expected input by examining the current parser context and

antlr-kotlin-runtime/src/commonMain/kotlin/org/antlr/v4/kotlinruntime/BailErrorStrategy.kt

@@ -46,7 +46,7 @@ public class BailErrorStrategy : DefaultErrorStrategy() {
 
     while (context != null) {
       context.exception = e
-      context = context.readParent()
+      context = context.getParent()
     }
 
     throw ParseCancellationException(e)
@@ -63,7 +63,7 @@ public class BailErrorStrategy : DefaultErrorStrategy() {
 
     while (context != null) {
       context.exception = e
-      context = context.readParent()
+      context = context.getParent()
     }
 
     throw ParseCancellationException(e)

antlr-kotlin-runtime/src/commonMain/kotlin/org/antlr/v4/kotlinruntime/DefaultErrorStrategy.kt

@@ -735,7 +735,7 @@ public open class DefaultErrorStrategy : ANTLRErrorStrategy {
       val rt = invokingState!!.transition(0) as RuleTransition
       val follow = atn.nextTokens(rt.followState)
       recoverSet.addAll(follow)
-      ctx = ctx.readParent()
+      ctx = ctx.getParent()
     }
 
     recoverSet.remove(Token.EPSILON)

antlr-kotlin-runtime/src/commonMain/kotlin/org/antlr/v4/kotlinruntime/Parser.kt

@@ -49,8 +49,10 @@ public abstract class Parser(input: TokenStream) : Recognizer<Token, ParserATNSi
     }
 
     override fun exitEveryRule(ctx: ParserRuleContext) {
-      if (ctx.children is ArrayList<*>) {
-        (ctx.children as ArrayList<*>).trimToSize()
+      val children = ctx.children
+
+      if (children is ArrayList<*>) {
+        children.trimToSize()
       }
     }
   }
@@ -584,7 +586,7 @@ public abstract class Parser(input: TokenStream) : Recognizer<Token, ParserATNSi
     ErrorNodeImpl(t)
 
   protected open fun addContextToParseTree() {
-    val parent = context!!.readParent()
+    val parent = context!!.getParent()
 
     // Add current context to parent if we have a parent
     parent?.addChild(context!!)
@@ -620,7 +622,7 @@ public abstract class Parser(input: TokenStream) : Recognizer<Token, ParserATNSi
     // Trigger event on context, before it reverts to parent
     triggerExitRuleEvent()
     state = context!!.invokingState
-    context = context!!.readParent()
+    context = context!!.getParent()
   }
 
   public fun enterOuterAlt(localctx: ParserRuleContext, altNum: Int) {
@@ -629,7 +631,7 @@ public abstract class Parser(input: TokenStream) : Recognizer<Token, ParserATNSi
     // If we have new localctx, make sure we replace existing ctx
     // that is previous child of parse tree
     if (buildParseTree && context !== localctx) {
-      val parent = context!!.readParent()
+      val parent = context!!.getParent()
 
       if (parent != null) {
         parent.removeLastChild()
@@ -657,7 +659,7 @@ public abstract class Parser(input: TokenStream) : Recognizer<Token, ParserATNSi
    */
   public open fun pushNewRecursionContext(localctx: ParserRuleContext, state: Int, ruleIndex: Int) {
     val previous = context
-    previous!!.assignParent(localctx)
+    previous!!.setParent(localctx)
     previous.invokingState = state
     previous.stop = _input.LT(-1)
 
@@ -683,14 +685,14 @@ public abstract class Parser(input: TokenStream) : Recognizer<Token, ParserATNSi
     if (parseListeners.isNotEmpty()) {
       while (context !== _parentctx) {
         triggerExitRuleEvent()
-        context = context!!.readParent()
+        context = context!!.getParent()
       }
     } else {
       context = _parentctx
     }
 
     // Hook into tree
-    retCtx!!.assignParent(_parentctx)
+    retCtx!!.setParent(_parentctx)
 
     if (buildParseTree && _parentctx != null) {
       // Add return ctx into invoking rule's tree
@@ -706,7 +708,7 @@ public abstract class Parser(input: TokenStream) : Recognizer<Token, ParserATNSi
         return p
       }
 
-      p = p.readParent()
+      p = p.getParent()
     }
 
     return null
@@ -757,7 +759,7 @@ public abstract class Parser(input: TokenStream) : Recognizer<Token, ParserATNSi
         return true
       }
 
-      ctx = ctx.readParent()
+      ctx = ctx.getParent()
     }
 
     return following.contains(Token.EPSILON) && symbol == Token.EOF
@@ -795,7 +797,7 @@ public abstract class Parser(input: TokenStream) : Recognizer<Token, ParserATNSi
         stack.add(ruleNames[ruleIndex])
       }
 
-      p = p.readParent()
+      p = p.getParent()
     }
 
     return stack

antlr-kotlin-runtime/src/commonMain/kotlin/org/antlr/v4/kotlinruntime/ParserRuleContext.kt

@@ -41,23 +41,33 @@ public open class ParserRuleContext : RuleContext {
     public val EMPTY: ParserRuleContext = ParserRuleContext()
   }
 
+  // This does not exist in the Java runtime
+  public val position: Position?
+    get() {
+      val start = this.start
+      val stop = this.stop
+
+      if (start != null && stop != null) {
+        val endPoint = stop.endPoint()
+
+        if (endPoint != null) {
+          return Position(start.startPoint(), endPoint)
+        }
+      }
+
+      return null
+    }
+
   /**
    * If we are debugging or building a parse tree for a visitor,
    * we need to track all the tokens and rule invocations associated
    * with this rule's context. This is empty for parsing w/o tree constr.
    * operation because we don't have the need to track the details about
    * how we parse this rule.
    */
+  @JvmField
   public var children: MutableList<ParseTree>? = null
 
-  // This does not exist in the Java runtime
-  public val position: Position?
-    get() = if (start != null && stop?.endPoint() != null) {
-      Position(start!!.startPoint(), stop!!.endPoint()!!)
-    } else {
-      null
-    }
-
   /**
    * The initial token in this context.
    *
@@ -81,6 +91,7 @@ public open class ParserRuleContext : RuleContext {
    *
    * If the rule successfully completed, this is `null`.
    */
+  @JvmField
   public var exception: RecognitionException? = null
 
   override val childCount: Int
@@ -98,11 +109,26 @@ public open class ParserRuleContext : RuleContext {
       }
     }
 
+  // Override to make the type more specific
+  override val ruleContext: ParserRuleContext
+    get() = this
+
+  // Override to make the type more specific
+  override val payload: ParserRuleContext
+    get() = this
+
   public constructor()
   public constructor(parent: ParserRuleContext?, invokingStateNumber: Int) : super(parent, invokingStateNumber)
 
-  override fun readParent(): ParserRuleContext? =
-    super.readParent() as ParserRuleContext?
+  // Override to make the type more specific
+  override fun getParent(): ParserRuleContext? =
+    parent as ParserRuleContext?
+
+  override fun setParent(value: RuleContext?) {
+    // Although we could assign 'value' straight away, we cast it
+    // to ensure we are dealing with a compatible type
+    parent = value as ParserRuleContext?
+  }
 
   /**
    * Copy a context (I'm deliberately not using copy constructor) to avoid
@@ -153,12 +179,12 @@ public open class ParserRuleContext : RuleContext {
    * Other [addChild] methods call this.
    *
    * We cannot set the parent pointer of the incoming node
-   * because the existing interfaces do not have a [assignParent]
+   * because the existing interfaces do not have a [setParent]
    * method and I don't want to break backward compatibility for this.
    *
    * @since 4.7
    */
-  public fun <T : ParseTree> addAnyChild(t: T): T {
+  public open fun <T : ParseTree> addAnyChild(t: T): T {
     var childrenTemp = children
 
     if (childrenTemp == null) {
@@ -170,14 +196,14 @@ public open class ParserRuleContext : RuleContext {
     return t
   }
 
-  public fun addChild(ruleInvocation: RuleContext): RuleContext =
+  public open fun addChild(ruleInvocation: RuleContext): RuleContext =
     addAnyChild(ruleInvocation)
 
   /**
    * Add a token leaf node child and force its parent to be this node.
    */
-  public fun addChild(t: TerminalNode): TerminalNode {
-    t.assignParent(this)
+  public open fun addChild(t: TerminalNode): TerminalNode {
+    t.setParent(this)
     return addAnyChild(t)
   }
 
@@ -186,8 +212,8 @@ public open class ParserRuleContext : RuleContext {
    *
    * @since 4.7
    */
-  public fun addErrorNode(errorNode: ErrorNode): ErrorNode {
-    errorNode.assignParent(this)
+  public open fun addErrorNode(errorNode: ErrorNode): ErrorNode {
+    errorNode.setParent(this)
     return addAnyChild(errorNode)
   }
 
@@ -197,7 +223,7 @@ public open class ParserRuleContext : RuleContext {
    *
    * If we have `# label`, we will need to remove generic `ruleContext` object.
    */
-  public fun removeLastChild() {
+  public open fun removeLastChild() {
     val tempChildren = children
     tempChildren?.removeAt(tempChildren.size - 1)
   }
@@ -211,7 +237,7 @@ public open class ParserRuleContext : RuleContext {
     }
   }
 
-  public fun <T : ParseTree> getChild(ctxType: KClass<T>, i: Int): T? {
+  public open fun <T : ParseTree> getChild(ctxType: KClass<T>, i: Int): T? {
     val tempChildren = children
 
     if (tempChildren == null || i < 0 || i >= tempChildren.size) {
@@ -235,7 +261,7 @@ public open class ParserRuleContext : RuleContext {
     return null
   }
 
-  public fun getToken(ttype: Int, i: Int): TerminalNode? {
+  public open fun getToken(ttype: Int, i: Int): TerminalNode? {
     val tempChildren = children
 
     if (tempChildren == null || i < 0 || i >= tempChildren.size) {
@@ -262,7 +288,7 @@ public open class ParserRuleContext : RuleContext {
     return null
   }
 
-  public fun getTokens(ttype: Int): List<TerminalNode> {
+  public open fun getTokens(ttype: Int): List<TerminalNode> {
     val tempChildren = children ?: return emptyList()
     val tokens = ArrayList<TerminalNode>()
 
@@ -279,10 +305,10 @@ public open class ParserRuleContext : RuleContext {
     return tokens
   }
 
-  public fun <T : ParserRuleContext> getRuleContext(ctxType: KClass<T>, i: Int): T? =
+  public open fun <T : ParserRuleContext> getRuleContext(ctxType: KClass<T>, i: Int): T? =
     getChild(ctxType, i)
 
-  public fun <T : ParserRuleContext> getRuleContexts(ctxType: KClass<T>): List<T> {
+  public open fun <T : ParserRuleContext> getRuleContexts(ctxType: KClass<T>): List<T> {
     val tempChildren = children ?: return emptyList()
     val contexts = ArrayList<T>()
 
@@ -299,7 +325,7 @@ public open class ParserRuleContext : RuleContext {
   /**
    * Used for rule context info debugging during parse-time, not so much for ATN debugging.
    */
-  public fun toInfoString(recognizer: Parser): String {
+  public open fun toInfoString(recognizer: Parser): String {
     val rules = recognizer.getRuleInvocationStack(this).toMutableList()
     rules.reverse()
     return "ParserRuleContext$rules{start=$start, stop=$stop}"

antlr-kotlin-runtime/src/commonMain/kotlin/org/antlr/v4/kotlinruntime/RuleContext.kt

@@ -8,6 +8,7 @@ import org.antlr.v4.kotlinruntime.tree.ParseTree
 import org.antlr.v4.kotlinruntime.tree.ParseTreeVisitor
 import org.antlr.v4.kotlinruntime.tree.RuleNode
 import org.antlr.v4.kotlinruntime.tree.Trees
+import kotlin.jvm.JvmField
 
 /**
  * A rule context is a record of a single rule invocation.
@@ -68,7 +69,8 @@ public open class RuleContext : RuleNode {
   /**
    * What context invoked this rule?
    */
-  public var parent: RuleContext? = null
+  @JvmField
+  protected var parent: RuleContext? = null
 
   /**
    * What state invoked the rule associated with this context?
@@ -77,6 +79,7 @@ public open class RuleContext : RuleNode {
    * If [parent] is `null`, this should be `-1` as this context
    * object represents the start rule.
    */
+  @JvmField
   public var invokingState: Int = -1
 
   /**
@@ -151,14 +154,14 @@ public open class RuleContext : RuleNode {
     this.invokingState = invokingState
   }
 
-  override fun readParent(): RuleContext? =
+  override fun getParent(): RuleContext? =
     parent
 
-  override fun assignParent(value: RuleContext?) {
+  override fun setParent(value: RuleContext?) {
     parent = value
   }
 
-  public fun depth(): Int {
+  public open fun depth(): Int {
     var n = 0
     var p: RuleContext? = this
 
@@ -191,7 +194,7 @@ public open class RuleContext : RuleNode {
    *
    * Print just a node if this is a leaf.
    */
-  public fun toStringTree(ruleNames: List<String>?): String =
+  public open fun toStringTree(ruleNames: List<String>?): String =
     Trees.toStringTree(this, ruleNames)
 
   override fun toStringTree(): String =
@@ -201,7 +204,7 @@ public open class RuleContext : RuleNode {
     toString(ruleNames = null, stop = null)
 
   // recog null unless ParserRuleContext, in which case we use subclass toString(...)
-  public fun toString(recog: Recognizer<*, *>?, stop: RuleContext = ParserRuleContext.EMPTY): String {
+  public open fun toString(recog: Recognizer<*, *>?, stop: RuleContext = ParserRuleContext.EMPTY): String {
     val ruleNames = recog?.ruleNames
     val ruleNamesList = if (ruleNames != null) {
       listOf(*ruleNames)
@@ -212,7 +215,7 @@ public open class RuleContext : RuleNode {
     return toString(ruleNamesList, stop)
   }
 
-  public fun toString(ruleNames: List<String>?, stop: RuleContext? = null): String {
+  public open fun toString(ruleNames: List<String>?, stop: RuleContext? = null): String {
     val buf = StringBuilder()
     var p: RuleContext? = this
     buf.append("[")

antlr-kotlin-runtime/src/commonMain/kotlin/org/antlr/v4/kotlinruntime/Token.kt

@@ -117,10 +117,8 @@ public interface Token {
   public fun startPoint(): Point =
     Point(line, charPositionInLine)
 
-  public fun endPoint(): Point? =
-    if (text == null) {
-      null
-    } else {
-      Point(line, charPositionInLine).advance(text!!)
-    }
+  public fun endPoint(): Point? {
+    val text = this.text ?: return null
+    return Point(line, charPositionInLine).advance(text)
+  }
 }