Antlr MismatchedSetException During Interpretation
- by user1646481
I am new to Antlr and I have defined a basic grammar using Antlr 3. The grammar compiles and ANTLRWorks generates the Parser and Lexer code without any problems.
The grammar can be seen below:
grammar i;
@header {
package i;
}
module : 'Module1'| 'Module2';
object : 'I';
objectType : 'Name';
filters : EMPTY | 'WHERE' module;
table : module object objectType;
STRING : ('a'..'z'|'A'..'Z')+;
EMPTY : ' ';
The problem is that when I interpret the table Parser I get a MismatchedSetException. This is due to having the EMPTY. As soon as I remove EMPTY from the grammar, the interpretation works. I have looked on the Antlr website and some other examples and the Empty space is ' '. I am not sure what to do. I need this EMPTY.
As soon as I change the EMPTY to be the following:
EMPTY : '';
instead of:
EMPTY : ' ';
It actually interprets it. However, I am getting the following Exception:
Interpreting...
[10:57:23] problem matching token at 1:4 NoViableAltException(' '@[1:1: Tokens : ( T__4 | T__5 | T__6 | T__7 | T__8 | T__9 | T__10 | T__11 | T__12 | T__13 | T__14 | T__15 | T__16 );])
[10:57:23] problem matching token at 1:9 NoViableAltException(' '@[1:1: Tokens : ( T__4 | T__5 | T__6 | T__7 | T__8 | T__9 | T__10 | T__11 | T__12 | T__13 | T__14 | T__15 | T__16 );])
When I take out the EMPTY, there are no problems at all.
I hope you can help.
