teach cqlsh to ignore comments

Patch by eevans; reviewed by gdusbabek for CASSANDRA-2488


git-svn-id: https://svn.apache.org/repos/asf/cassandra/branches/cassandra-0.8@1095149 13f79535-47bb-0310-9956-ffa450edef68

drivers/py/cqlsh

@@ -64,12 +64,33 @@ class Shell(cmd.Cmd):
 
         self.statement = StringIO()
         self.color = color
+        self.in_comment = False
 
     def reset_statement(self):
         self.set_prompt(Shell.default_prompt)
         self.statement.truncate(0)
 
     def get_statement(self, line):
+        if self.in_comment:
+            if "*/" in line:
+                fragment = line[line.index("*/")+2:]
+                if fragment.strip():
+                    line = fragment
+                    self.in_comment = False
+                else:
+                    self.in_comment = False
+                    self.set_prompt(Shell.default_prompt)
+                    return None
+            else:
+                return None
+
+        if "/*" in line and (not self.in_comment):
+            self.in_comment = True
+            self.set_prompt(Shell.continue_prompt)
+            if line.lstrip().index("/*") != 0:
+                self.statement.write(line[:line.lstrip().index("/*")])
+            return None
+
         self.statement.write("%s\n" % line)
 
         if not line.endswith(";"):
@@ -82,8 +103,14 @@ class Shell(cmd.Cmd):
             self.reset_statement()
 
     def default(self, arg):
-        if not arg.strip(): return
-        statement = self.get_statement(arg)
+        def scrub_oneline_comments(s):
+            res = re.sub(r'\/\*.*\*\/', '', s)
+            res = re.sub(r'--.*$', '', res)
+            return res
+
+        input = scrub_oneline_comments(arg)
+        if not input.strip(): return
+        statement = self.get_statement(input)
         if not statement: return
 
         cursor = self.conn.cursor()