refactored CommonTokenStream.js to use es6 classes

fix: dont wrap class in an object for export
fix: annotate adjustSeekIndex with Number type to avoid warning
use const for better scoping
use jsdoc

runtime/JavaScript/src/antlr4/BufferedTokenStream.js

@@ -214,8 +214,8 @@ class BufferedTokenStream extends TokenStream {
 	 * that
 	 * the seek target is always an on-channel token.</p>
 	 *
-	 * @param i The target token index.
+	 * @param {Number} i The target token index.
-	 * @return The adjusted target token index.
+	 * @return {Number} The adjusted target token index.
 	 */
 	adjustSeekIndex(i) {
 		return i;

runtime/JavaScript/src/antlr4/CommonTokenStream.js

@@ -1,57 +1,52 @@
-//
 /* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
  * Use of this file is governed by the BSD 3-clause license that
  * can be found in the LICENSE.txt file in the project root.
  */
-///
 
-//
-// This class extends {@link BufferedTokenStream} with functionality to filter
-// token streams to tokens on a particular channel (tokens where
-// {@link Token//getChannel} returns a particular value).
-//
-// <p>
-// This token stream provides access to all tokens by index or when calling
-// methods like {@link //getText}. The channel filtering is only used for code
-// accessing tokens via the lookahead methods {@link //LA}, {@link //LT}, and
-// {@link //LB}.</p>
-//
-// <p>
-// By default, tokens are placed on the default channel
-// ({@link Token//DEFAULT_CHANNEL}), but may be reassigned by using the
-// {@code ->channel(HIDDEN)} lexer command, or by using an embedded action to
-// call {@link Lexer//setChannel}.
-// </p>
-//
-// <p>
-// Note: lexer rules which use the {@code ->skip} lexer command or call
-// {@link Lexer//skip} do not produce tokens at all, so input text matched by
-// such a rule will not be available as part of the token stream, regardless of
-// channel.</p>
-///
 
-var Token = require('./Token').Token;
+const Token = require('./Token').Token;
-var BufferedTokenStream = require('./BufferedTokenStream');
+const BufferedTokenStream = require('./BufferedTokenStream');
 
-function CommonTokenStream(lexer, channel) {
+/**
-	BufferedTokenStream.call(this, lexer);
+ * This class extends {@link BufferedTokenStream} with functionality to filter
+ * token streams to tokens on a particular channel (tokens where
+ * {@link Token//getChannel} returns a particular value).
+ *
+ * <p>
+ * This token stream provides access to all tokens by index or when calling
+ * methods like {@link //getText}. The channel filtering is only used for code
+ * accessing tokens via the lookahead methods {@link //LA}, {@link //LT}, and
+ * {@link //LB}.</p>
+ *
+ * <p>
+ * By default, tokens are placed on the default channel
+ * ({@link Token//DEFAULT_CHANNEL}), but may be reassigned by using the
+ * {@code ->channel(HIDDEN)} lexer command, or by using an embedded action to
+ * call {@link Lexer//setChannel}.
+ * </p>
+ *
+ * <p>
+ * Note: lexer rules which use the {@code ->skip} lexer command or call
+ * {@link Lexer//skip} do not produce tokens at all, so input text matched by
+ * such a rule will not be available as part of the token stream, regardless of
+ * channel.</p>
+ */
+class CommonTokenStream extends BufferedTokenStream {
+    constructor(lexer, channel) {
+        super(lexer);
         this.channel = channel===undefined ? Token.DEFAULT_CHANNEL : channel;
-    return this;
     }
 
-CommonTokenStream.prototype = Object.create(BufferedTokenStream.prototype);
+    adjustSeekIndex(i) {
-CommonTokenStream.prototype.constructor = CommonTokenStream;
-
-CommonTokenStream.prototype.adjustSeekIndex = function(i) {
         return this.nextTokenOnChannel(i, this.channel);
-};
+    }
 
-CommonTokenStream.prototype.LB = function(k) {
+    LB(k) {
         if (k===0 || this.index-k<0) {
             return null;
         }
-    var i = this.index;
+        let i = this.index;
-    var n = 1;
+        let n = 1;
         // find k good tokens looking backwards
         while (n <= k) {
             // skip off-channel tokens
@@ -62,9 +57,9 @@ CommonTokenStream.prototype.LB = function(k) {
             return null;
         }
         return this.tokens[i];
-};
+    }
 
-CommonTokenStream.prototype.LT = function(k) {
+    LT(k) {
         this.lazyInit();
         if (k === 0) {
             return null;
@@ -72,8 +67,8 @@ CommonTokenStream.prototype.LT = function(k) {
         if (k < 0) {
             return this.LB(-k);
         }
-    var i = this.index;
+        let i = this.index;
-    var n = 1; // we know tokens[pos] is a good one
+        let n = 1; // we know tokens[pos] is a good one
         // find k good tokens
         while (n < k) {
             // skip off-channel tokens, but make sure to not look past EOF
@@ -83,14 +78,14 @@ CommonTokenStream.prototype.LT = function(k) {
             n += 1;
         }
         return this.tokens[i];
-};
+    }
 
-// Count EOF just once.///
+    // Count EOF just once.
-CommonTokenStream.prototype.getNumberOfOnChannelTokens = function() {
+    getNumberOfOnChannelTokens() {
-    var n = 0;
+        let n = 0;
         this.fill();
-    for (var i =0; i< this.tokens.length;i++) {
+        for (let i =0; i< this.tokens.length;i++) {
-        var t = this.tokens[i];
+            const t = this.tokens[i];
             if( t.channel===this.channel) {
                 n += 1;
             }
@@ -99,6 +94,7 @@ CommonTokenStream.prototype.getNumberOfOnChannelTokens = function() {
             }
         }
         return n;
-};
+    }
+}
 
-exports.CommonTokenStream = CommonTokenStream;
+module.exports = CommonTokenStream;

runtime/JavaScript/src/antlr4/index.js

@@ -13,7 +13,7 @@ exports.CharStreams = require('./CharStreams');
 exports.CommonToken = require('./Token').CommonToken;
 exports.InputStream = require('./InputStream').InputStream;
 exports.FileStream = require('./FileStream').FileStream;
-exports.CommonTokenStream = require('./CommonTokenStream').CommonTokenStream;
+exports.CommonTokenStream = require('./CommonTokenStream');
 exports.Lexer = require('./Lexer').Lexer;
 exports.Parser = require('./Parser').Parser;
 var pc = require('./PredictionContext');