增强测试

git-svn-id: http://code.alibabatech.com/svn/druid/trunk@984 b9813039-fb51-4c41-a8b9-e21c2acb5095

src/main/java/com/alibaba/druid/sql/parser/Lexer.java

@@ -76,10 +76,39 @@ public class Lexer {
 
     protected boolean                          skipComment = true;
 
+    private SavePoint                          savePoint   = null;
+
     public Lexer(String input){
         this(input, true);
     }
 
+    private static class SavePoint {
+
+        int   bp;
+        int   sp;
+        int   np;
+        char   ch;
+        Token token;
+    }
+
+    public void mark() {
+        SavePoint savePoint = new SavePoint();
+        savePoint.bp = bp;
+        savePoint.sp = sp;
+        savePoint.np = np;
+        savePoint.ch = ch;
+        savePoint.token = token;
+        this.savePoint = savePoint;
+    }
+
+    public void reset() {
+        this.bp = savePoint.bp;
+        this.sp = savePoint.sp;
+        this.np = savePoint.np;
+        this.ch = savePoint.ch;
+        this.token = savePoint.token;
+    }
+
     public Lexer(String input, boolean skipComment){
         this(input.toCharArray(), input.length(), skipComment);
     }