[antlr-interest] [C target] About disable recovery ... [Solution?]

[Ruslan Zasukhin]

Hi All,

I want describe for archive of this list solution which I have found after 3
days learning issue.

So ... Story is.

1) I have read book ... Here info only for Java ... Overrite this. Catch
exception.. But in C no exception, so it is clear I must find info for C.

2) I jump to site -> docs -> C target   ===>  NOTHING ?
    but should be info + example here, because C target
    differs from Java. No exceptions.

3) I start search list archive... Nothing useful except last letter from
guy, which note that C comment says we must override mismatchRecover(),
But there is no such function, probably it was renamed to
recoverFromMismatchedToken()
 

4) Okay, I try override this function in MY ,cpp file.
But... Ops.  mismatch() function,  is STATIC, so I cannot link to it from my
sourcs.

Jim have suggest copy to my sources mismatch() also,
Okay I try that and ... It even not compiles, because mismatch() calls other
static funcs ...   

Dirty force then:  I make it in the antlr3baserecognizer.c

Compiles links ...  HAPPY -> start do tests  ....
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

And I see that for example such SQL query with error
    
    "DRO TABLE T1"

Still do 3 iterations ...

Debugging shows me that I even do not get into recoverFromMismatchedToken()
Oops again...

After some debugging, I have note, that each rule, always calls recover(),
and exactly this method clears error flag.

So I do next attempt:  I make own simple recover()

void vdb_recover_off( pANTLR3_BASE_RECOGNIZER recognizer )
{
    return;
}


And replace default in the parser:

@parser::apifuncs
{
    // Install custom error message display
    //
    RECOGNIZER->displayRecognitionError = vdb_BuildRecognitionErrorStr;
    RECOGNIZER->recover = vdb_recover_off;



And finally !!!!    It works as I want that ...
Parser builds error string and stops right on the first work  DRO.
 
I will write also now separate letter to Terrence and Jim,
where I will try explain why such simple thing as
        option RECOVER = FALSE

Should not take 3 days from users of ANTLR :)

I hope this letter will save time to future C users of ANTRL.


===================
P.S. 

Also while I did learn this recover dances on ANTLR,
And read that we must override recoverFromMismatchedToken()
I have asked self:

here exists yet 
    recoverFromMismatchedSet(),
    recoverFromMismatchedElement
    recover()


Why only ONE that function should be overriden?

I think in Docs, Books, Comments, this should be explained also in clean
way. Right?


-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]