[antlr-interest] sentences of a grammar

[Loring Craymer]

Gerrie--

Could you post your work to the antlr.org site?  From the response I got
from mentioning your post, I believe that the lack of response to your
original message was an oversight.

--Loring


> -----Original Message-----
> From: antlr-interest-bounces at antlr.org [mailto:antlr-interest-
> bounces at antlr.org] On Behalf Of Gerrie Myburg [ MTN - Innovation Centre ]
> Sent: Friday, June 09, 2006 2:24 AM
> To: antlr-interest at antlr.org
> Subject: [antlr-interest] sentences of a grammar
> 
> I write some code that will take an antlr grammar definition, create a
> graph from the grammar and will try to generate all possible sentences
> from the grammar. The following rules are used to avoid infinite length
> sentences.
> 
> (a)* is rewritten as ( |a|aa| ... ) to a max limit
> (a)+ is rewritten as ( a|aa| ... ) to a max limit
> (a)? is rewritten as ( |a)
> 
> Recursive loops are avoided by entering the loop once and once only.
> Infinite recursion is detected and reported.
> 
> The sentences are created by finding all possible paths in the grammar
> graph. Backtracking is used in the graph at every point in the path
> where a '|' is encountered.
> 
> Token references are resolved at the moment by referring to a map of
> token ref definitions. If no definition is supplied then the token ref
> string is used instead.
> 
> The code is meant to be used on a grammar that has already been passed
> by the antlr compiler.
> 
> I wrote the code to test the tree parser of a sql compiler. While
> testing the code I found that the number of sentences generated for some
> of the sql rules is enormous. The number of sentences can run into the
> millions for most rules. The antlr grammar in turn yields about 8000
> sentences.
> 
> The only sensible way of using the code is to generate a sentence then
> feed it to the destination compiler directly instead of writing out a
> file.
> 
> The sentences are not necessarily semantically correct at the moment. In
> fact I am sure that it is not the case.
> 
> Does anyone want me to upload the code to the antlr website?
> 
> 
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