Generalized LR

Introduction

A parsing algorithm that maintains multiple LR parsing states in parallel.

From Object Oriented Tree Traversal With JJForester :

GeneralizedLR parsing removes the restriction to a non-ambiguous subclass of the context-free grammars, such as the LR(k) class. This allows a maximally natural expression of the intended syntax; no more need for `bending over backwards' to encode the intended grammar in a restricted subclass. Furthermore, generalized parsing leads to better modularity and allows `as-is' syntax reuse.

Implementations

Implementations of GLR using a separate scanner

• ElkHound is GLR parser generator
• Bison includes an GLR parser.
• PyGgy A Python parser generator that generates SLR tables for a GLR parsing engine.

Implementations of Scannerless Generalized LR

• SGLR is a Scannerless Generalized LR parser
• DParser is Scannerless Generalized LR parser generator.

The maintainers of Elkhound maintain a list of implementations as well.