added convenience getText(ctx) method to TokenStream. unlikley to need in CharStream and can get another way

runtime/Java/src/org/antlr/v4/runtime/BufferedTokenStream.java

@@ -267,6 +267,9 @@ public class BufferedTokenStream<T extends Token> implements TokenStream {
 		return buf.toString();
     }
 
+	@Override
+	public String getText(RuleContext ctx) { return getText(ctx.getSourceInterval()); }
+
     @Override
     public String getText(Token start, Token stop) {
         if ( start!=null && stop!=null ) {

runtime/Java/src/org/antlr/v4/runtime/TokenStream.java

@@ -43,11 +43,6 @@ public interface TokenStream extends SymbolStream<Token> {
     @Override
     public Token LT(int k);
 
-	/** How far ahead has the stream been asked to look?  The return
-	 *  value is a valid index from 0..n-1.
-	 */
-//	int range();
-
 	/** Get a token at an absolute index i; 0..n-1.  This is really only
 	 *  needed for profiling and debugging and token stream rewriting.
 	 *  If you don't want to buffer up tokens, then this method makes no
@@ -72,6 +67,8 @@ public interface TokenStream extends SymbolStream<Token> {
 	 */
 	public String getText(Interval interval);
 
+	public String getText(RuleContext ctx);
+
 	/** Because the user is not required to use a token with an index stored
 	 *  in it, we must provide a means for two token objects themselves to
 	 *  indicate the start/end location.  Most often this will just delegate

runtime/Java/src/org/antlr/v4/runtime/UnbufferedTokenStream.java

@@ -88,7 +88,12 @@ public class UnbufferedTokenStream<T extends Token>
         throw new UnsupportedOperationException("unbuffered stream can't give strings");
     }
 
-    @Override
+	@Override
+	public String getText(RuleContext ctx) {
+		throw new UnsupportedOperationException("unbuffered stream can't give strings");
+	}
+
+	@Override
     public int LA(int i) { return LT(i).getType(); }
 
     @Override

tool/test/org/antlr/v4/test/BaseTest.java

@@ -40,6 +40,7 @@ import org.antlr.v4.runtime.CharStream;
 import org.antlr.v4.runtime.CommonToken;
 import org.antlr.v4.runtime.CommonTokenStream;
 import org.antlr.v4.runtime.Lexer;
+import org.antlr.v4.runtime.RuleContext;
 import org.antlr.v4.runtime.Token;
 import org.antlr.v4.runtime.TokenSource;
 import org.antlr.v4.runtime.TokenStream;
@@ -1098,7 +1099,12 @@ public abstract class BaseTest {
 
 		@Override
 		public String getText(Interval interval) {
-			return null;
+			throw new UnsupportedOperationException("can't give strings");
+		}
+
+		@Override
+		public String getText(RuleContext ctx) {
+			throw new UnsupportedOperationException("can't give strings");
 		}
 
 		@Override