From cdb420fddeb7d1a9ac3b89edb7b233c4a6d7c64d Mon Sep 17 00:00:00 2001
From: Terence Parr <parrt@antlr.org>
Date: Tue, 14 Feb 2012 15:01:03 -0800
Subject: [PATCH] got implementation of getters in!  Fixes #8

---
 .../antlr/v4/runtime/ParserRuleContext.java   | 56 +++++++++++++++----
 .../src/org/antlr/v4/runtime/RuleContext.java | 17 ------
 .../v4/tool/templates/codegen/Java/Java.stg   | 30 ++++++++--
 3 files changed, 69 insertions(+), 34 deletions(-)

diff --git a/runtime/Java/src/org/antlr/v4/runtime/ParserRuleContext.java b/runtime/Java/src/org/antlr/v4/runtime/ParserRuleContext.java
index c51775dd2..304ab24f0 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/ParserRuleContext.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/ParserRuleContext.java
@@ -131,17 +131,6 @@ public class ParserRuleContext<Symbol> extends RuleContext {
 		this(parent, parent!=null ? parent.s : -1 /* invoking state */, stateNumber);
 	}
 
-//	@Override
-//	public int hashCode() {
-//		return super.hashCode() + s;
-//	}
-//
-//	@Override
-//	public boolean equals(Object o) {
-//		if ( !super.equals(o) ) return false;
-//		return s != ((RuleContext)o).s; // must be parsing the same location in the ATN
-//	}
-
 	// Double dispatch methods
 
 	public void enterRule(ParseTreeListener<Symbol> listener) { }
@@ -190,6 +179,51 @@ public class ParserRuleContext<Symbol> extends RuleContext {
 		return children!=null ? children.get(i) : null;
 	}
 
+	public Object getChild(Class ctxType, int i) {
+		if ( children==null ) throw new UnsupportedOperationException("there are no children");
+		int j = -1; // what element have we found with ctxType?
+		for (Object o : children) {
+			if ( o.getClass().isInstance(ctxType) ) {
+				j++;
+				if ( j == i ) return o;
+			}
+		}
+		return null;
+	}
+
+	public Token getToken(int ttype, int i) {
+		if ( children==null ) throw new UnsupportedOperationException("there are no children");
+		return (Token)getChild(Token.class, i);
+	}
+
+	public List<Token> getTokens(int ttype) {
+		if ( children==null ) throw new UnsupportedOperationException("there are no children");
+		List<Token> tokens = null;
+		for (Object o : children) {
+			if ( o instanceof Token ) {
+				if ( tokens==null ) tokens = new ArrayList<Token>();
+				tokens.add((Token)o);
+			}
+		}
+		return tokens;
+	}
+
+	public ParserRuleContext getRuleContext(Class ctxType, int i) {
+		return (ParserRuleContext)getChild(ctxType, i);
+	}
+
+	public List<? extends ParserRuleContext> getRuleContexts(Class ctxType) {
+		if ( children==null ) throw new UnsupportedOperationException("there are no children");
+		List<ParserRuleContext> contexts = null;
+		for (Object o : children) {
+			if ( o.getClass().isInstance(ctxType) ) {
+				if ( contexts==null ) contexts = new ArrayList<ParserRuleContext>();
+				contexts.add((ParserRuleContext)o);
+			}
+		}
+		return contexts;
+	}
+
 	@Override
 	public int getChildCount() { return children!=null ? children.size() : 0; }
 
diff --git a/runtime/Java/src/org/antlr/v4/runtime/RuleContext.java b/runtime/Java/src/org/antlr/v4/runtime/RuleContext.java
index 2d0113178..b762eb516 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/RuleContext.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/RuleContext.java
@@ -80,16 +80,6 @@ public class RuleContext implements ParseTree.RuleNode {
 
 	public RuleContext() {}
 
-//	public RuleContext(RuleContext parent) {
-//		this(parent, -1);
-//	}
-//
-//	public RuleContext(RuleContext parent, int stateNumber) {
-//		// capture state that called us as we create this context; use later for
-//		// return state in closure
-//		this(parent, parent != null ? parent.s : -1, stateNumber);
-//	}
-
 	public RuleContext(RuleContext parent, int invokingState) {
 		this.parent = parent;
 		//if ( parent!=null ) System.out.println("invoke "+stateNumber+" from "+parent);
@@ -103,13 +93,6 @@ public class RuleContext implements ParseTree.RuleNode {
 
 	@Override
 	public int hashCode() {
-//		int h = 0;
-//		RuleContext p = this;
-//		while ( p!=null ) {
-//			h += p.stateNumber;
-//			p = p.parent;
-//		}
-//		return h;
 		return cachedHashCode; // works with tests; don't recompute.
 	}
 
diff --git a/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg b/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg
index e315672a1..af8037353 100644
--- a/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg
+++ b/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg
@@ -493,12 +493,30 @@ TokenListDecl(t) ::= "public List\<Token> <t.name> = new ArrayList\<Token>();"
 RuleContextDecl(r) ::= "public <r.ctxName> <r.name>;"
 RuleContextListDecl(rdecl) ::= "public List\<<rdecl.ctxName>> <rdecl.name> = new ArrayList\<<rdecl.ctxName>>();"
 
-ContextTokenGetterDecl(t)      ::= "public Token <t.name>() { return null; }"
-ContextTokenListGetterDecl(t)  ::= "public List\<Token> <t.name>() { return null; }"
-ContextTokenListIndexedGetterDecl(t)  ::= "public Token <t.name>(int i) { return null; }"
-ContextRuleGetterDecl(r)       ::= "public <r.ctxName> <r.name>() { return null; }"
-ContextRuleListGetterDecl(r)   ::= "public List\<<r.ctxName>> <r.name>() { return null; }"
-ContextRuleListIndexedGetterDecl(r)   ::= "public <r.ctxName> <r.name>(int i) { return null; }"
+ContextTokenGetterDecl(t)      ::=
+    "public Token <t.name>() { return getToken(<parser.name>.<t.name>, 0); }"
+ContextTokenListGetterDecl(t)  ::=
+    "public List\<Token> <t.name>() { return getTokens(<parser.name>.<t.name>); }"
+ContextTokenListIndexedGetterDecl(t)  ::= <<
+public Token <t.name>(int i) {
+    return getToken(<parser.name>.<t.name>, i);
+}
+>>
+ContextRuleGetterDecl(r)       ::= <<
+public <r.ctxName> <r.name>() {
+    return (<r.ctxName>)getRuleContext(<r.ctxName>.class,0);
+}
+>>
+ContextRuleListGetterDecl(r)   ::= <<
+public List\<<r.ctxName>\> <r.name>() {
+    return (List\<<r.ctxName>\>)getRuleContexts(<r.ctxName>.class);
+}
+>>
+ContextRuleListIndexedGetterDecl(r)   ::= <<
+public <r.ctxName> <r.name>(int i) {
+    return (<r.ctxName>)getRuleContext(<r.ctxName>.class,i);
+}
+>>
 
 LexerRuleContext() ::= "RuleContext"