1 files changed, 70 insertions, 0 deletions
diff --git a/src/main/java/io/devnulllabs/openjava/syntax/RestorableTokenSource.java b/src/main/java/io/devnulllabs/openjava/syntax/RestorableTokenSource.java
new file mode 100644
index 0000000..d82c5af
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+++ b/src/main/java/io/devnulllabs/openjava/syntax/RestorableTokenSource.java
@@ -0,0 +1,70 @@
+/*
+ * RestorableTokenSource.java
+ *
+ * comments here.
+ *
+ * @author   Michiaki Tatsubori
+ * @version  %VERSION% %DATE%
+ * @see      java.lang.Object
+ *
+ * COPYRIGHT 1998 by Michiaki Tatsubori, ALL RIGHTS RESERVED.
+ */
+package io.devnulllabs.openjava.syntax;
+
+import io.devnulllabs.openjava.mop.Environment;
+import io.devnulllabs.openjava.tools.parser.Token;
+
+/**
+ * The class <code>RestorableTokenSource</code>
+ * <p>
+ * For example
+ * <pre>
+ * </pre>
+ * <p>
+ *
+ * @author   Michiaki Tatsubori
+ * @version  1.0
+ * @since    $Id: RestorableTokenSource.java,v 1.2 2003/02/19 02:54:31 tatsubori Exp $
+ * @see java.lang.Object
+ */
+public class RestorableTokenSource implements TokenSource {
+    private TokenSource tokenSource;
+    private Environment env;
+    private int pointer = 0;
+    private int offset = 0;
+
+    public RestorableTokenSource(TokenSource src, Environment env) {
+        this.tokenSource = src;
+        this.env = env;
+    }
+
+    public RestorableTokenSource(TokenSource src) {
+        this(src, null);
+    }
+
+    public Environment getEnvironment() {
+        return ((env == null) ? tokenSource.getEnvironment() : env);
+    }
+
+    public void assume() {
+        offset = pointer;
+    }
+    public void restore() {
+        pointer = offset;
+    }
+    public void fix() {
+        for (int i = offset; i < pointer; ++i) {
+            tokenSource.getNextToken();
+        }
+        pointer = 0;
+        offset = 0;
+    }
+    public Token getNextToken() {
+        return tokenSource.getToken(++pointer);
+    }
+
+    public Token getToken(int i) {
+        return tokenSource.getToken(pointer + i);
+    }
+
+}