Welcome to the LRTT parser home page


The LRTT parser (Left to Right Tree Traversal) is a PEG parser which deals with left recursive rules in "native mode", that is, without modifying the specified grammar with respect to priorities, except of course that every left recursion is delt with after all non recursive production heads have been tried.
The LRTTparser handles mutual left recursives rules at any depth.

The LRTT parser is a single Ocaml functor of less than 700 lines and is probably the smallest parser generator around, though it doesn't "generate" anything but directly runs the grammar defined as an Ocaml tree structure.

I am not specifically an Ocaml hacker and this is a quick and dirty alpha release, though perfectly usable as is demonstrated by the implementation of John Backus FP language from his 1977 Turing Award Lecture.

This project is now hosted at Ocaml Forge.

You may alternatively download the LRTT parser Beta 1.0 from here.
You may want to read the README for more information.

See also the latest CHANGES.

Comments are welcome.