1 files changed, 63 insertions, 0 deletions
diff --git a/runtime/JavaScript/src/org/antlr/runtime/ANTLRFileStream.js b/runtime/JavaScript/src/org/antlr/runtime/ANTLRFileStream.js
new file mode 100755
index 0000000..d2d0ea1
--- /dev/null
+++ b/runtime/JavaScript/src/org/antlr/runtime/ANTLRFileStream.js
@@ -0,0 +1,63 @@
+/** 
+ * Loads the contents of a file all at once and passes its contents off to
+ * {@link org.antlr.runtime.ANTLRStringStream}.
+ * Currently this class can only be used in the Rhino JS interpreter.
+ * @class
+ * @extends org.antlr.runtime.ANTLRStringStream
+ * @param {String} fileName path of the file to be loaded
+ * @param {String} [encoding] name of the charset used for decoding
+ */
+org.antlr.runtime.ANTLRFileStream = function(fileName, encoding) {
+    this.fileName = fileName;
+
+    // @todo need to add support for other JS interpreters that have file i/o
+    // hooks (SpiderMonkey and WSH come to mind).
+    var method;
+    if (org.antlr.env.ua.rhino) {
+        method = "loadFileUsingJava";
+    } else {
+        throw new Error(
+            "ANTLR File I/O is not supported in this JS implementation."
+        );
+    }
+
+    var data = this[method](fileName, encoding);
+    org.antlr.runtime.ANTLRFileStream.superclass.constructor.call(this, data);
+};
+
+org.antlr.lang.extend(org.antlr.runtime.ANTLRFileStream,
+                  org.antlr.runtime.ANTLRStringStream,
+/** @lends org.antlr.runtime.ANTLRFileStream.prototype */{
+    /**
+     * Get the file path from which the input was loaded.
+     * @returns {String} the file path from which the input was loaded
+     */
+    getSourceName: function() {
+        return this.fileName;
+    },
+
+    /**
+     * Read the file and return its contents as a JS string.
+     * @private
+     * @param {String} fileName path of the file to be loaded
+     * @param {String} [encoding] name of the charset used for decoding
+     * @returns {String} the contents of the file
+     */
+    loadFileUsingJava: function(fileName, encoding) {
+        // read the file using Java methods
+        var f = new java.io.File(fileName),
+            size = f.length(),
+            isr,
+            fis = new java.io.FileInputStream(f);
+        if (encoding) {
+            isr = new java.io.InputStreamReader(fis, encoding);
+        } else {
+            isr = new java.io.InputStreamReader(fis);
+        }
+        var data = java.lang.reflect.Array.newInstance(java.lang.Character.TYPE, size);
+        isr.read(data, 0, size);
+
+        // convert java char array to a javascript string
+        return new String(new java.lang.String(data));
+    }
+});