Description
PIG-3268 added case statement support. But conditions are currently not allowed in when branches. For example,
CASE WHEN i % 5 == 0 THEN '5n' WHEN i % 5 == 1 THEN '5n+1' WHEN i % 5 == 2 THEN '5n+2' WHEN i % 5 == 3 THEN '5n+3' ELSE '5n+4' END
This is invalid now. However, it will be useful if it's allowed.