[antlr-interest] MismatchedTokenException and how to find errors in ANTLRWorks

[shmuel siegel]

Jim Idle wrote:
> ....
>
> There isn't anything wrong with the tool, it is doing what you tell it 
> to do. The token isnt anonymous, it is called T66 or whatever, the 
> runtime doesn't know that you created it by specifying it in the parser. 
> So, I don't see why "anonymous token" would help you at all.
>
> .....
>> The tool needs to be patched, not users.
>>     
>
> A tool should strive to be as simple as possible, but no simpler :-) 
> While that statement makes sense, you are an under an obligation to 
> yourself to try to make sure you understand the tool too. Ironically, my 
> statement that literals in parsers are confusing is based entirely upon 
> your stated premise.
>
> Jim
I thought that another voice should jump in here. Even though Jim and I 
are usually on different sides of usability arguments (Jim takes the 
side of the ANTLR developer and I take the side of the ANTLR rule 
writer), I totally agree with him here. Not only is ANTLR doing what you 
told it to do, it is doing what you would want it to do if you were more 
experienced with the tool. Personally, I am amazed that ANTLR can 
distinguish between '+', '=', and '+='. Criticism of the tool should be 
postponed until you truly understand what the tool is doing.
ANTLR is a parser and lexer generator (okay, it is other things too). 
The fact that ANTLR lets you implicitly generate lexer rules by using 
literals in the parser does not change the fact that they are lexer 
rules and must conform to the lexer paradigm.

Shmuel