From 93d6f9fc54ea94664aa8623ace9963940a82a516 Mon Sep 17 00:00:00 2001
From: David Huynh <dfhuynh@gmail.com>
Date: Tue, 6 Apr 2010 06:18:07 +0000
Subject: [PATCH] Better error message for bad regular expressions in GEL.

git-svn-id: http://google-refine.googlecode.com/svn/trunk@388 7d457c2a-affb-35e4-300a-418c747d4874
---
 src/main/java/com/metaweb/gridworks/gel/Parser.java | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/metaweb/gridworks/gel/Parser.java b/src/main/java/com/metaweb/gridworks/gel/Parser.java
index e0ed9ff70..887ad3498 100644
--- a/src/main/java/com/metaweb/gridworks/gel/Parser.java
+++ b/src/main/java/com/metaweb/gridworks/gel/Parser.java
@@ -140,8 +140,13 @@ public class Parser {
         } else if (_token.type == TokenType.Regex) {
             RegexToken t = (RegexToken) _token;
             
-            eval = new LiteralExpr(Pattern.compile(_token.text, t.caseInsensitive ? Pattern.CASE_INSENSITIVE : 0));
-            next(false);
+            try {
+                Pattern pattern = Pattern.compile(_token.text, t.caseInsensitive ? Pattern.CASE_INSENSITIVE : 0);
+                eval = new LiteralExpr(pattern);
+                next(false);
+            } catch (Exception e) {
+                throw makeException("Bad regular expression (" + e.getMessage() + ")");
+            }
         } else if (_token.type == TokenType.Number) {
             eval = new LiteralExpr(((NumberToken)_token).value);
             next(false);