Browse thread
[Caml-list] Context Free Grammars?
[
Home
]
[ Index:
by date
|
by threads
]
[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
| Date: | -- (:) |
| From: | David McClain <David.McClain@A...> |
| Subject: | [Caml-list] Context Free Grammars? |
I think my mind has been poisoned from exposure to recursive descent parsing... I am running into a huge number of reduce/reduce conflicts in OCamlYacc. It is beginning to dawn on me that Yacc really is for context-free grammars... (that's what they said! only now I'm starting to realize it..) So the question is, does OCaml actually have a CFG description? I'm confused about the similarity of patterns and expression from the viewpoint of CFG description. They share many similarities, and in the correct context there can be no confusion. But when I try to generate a parser it appears that pieces of expression syntax and pieces of pattern syntax are confusing the parser. If the parser really ignores any kind of context -- such as the parent tree for the subproduction -- then the lack of any context knowledge would certainly be confusing. Anyone have any hints about syntax transformations so that CFG's can really be used here? I read a tremendous number of references that indicate how nasty these reduce/reduce conflicts can be. I believe them. Trouble is they don't go very far in explaining how to fix these conflicts, other than to state that "you have a mistake in your grammar". Some references do hint that syntax description transformations can become unwieldy and unnatural to read. I have to stop thinking like recursive descent and try to view the universe as flat-land... David McClain Senior Corporate Scientist Avisere, Inc. david.mcclain@avisere.com +1.520.390.7738 (USA) ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners