jplevyak / dparser

A Scannerless GLR parser/parser generater.

DParser

(you know... 'da parser)

Introduction

DParser is a simple but powerful tool for parsing. You can specify the form of the text to be parsed using a combination of regular expressions and grammar productions. Because of the parsing technique (technically a scannerless GLR parser based on the Tomita algorithm) there are no restrictions. The grammar can be ambiguous, right or left recursive, have any number of null productions, and because there is no separate tokenizer, can include whitespace in terminals and have terminals which are prefixes of other terminals. DParser handles not just well formed computer languages and data files, but just about any wacky situation that occurs in the real world. The result is natural grammars and powerful parsing.

Features

• Powerful GLR parsing
• Simple EBNF-style grammars and regular expression terminals
• State-specific symbol table
• Priorities and associativities for token and rules
• Built-in error recovery
• Can be compiled to work with or without the Boehm garbage collector
• Speculative actions (for semantic disambiguation)
• Auto-building of parse tree (optionally)
• Final actions as you go, or on the complete parse tree
• Tree walkers and default actions (multi-pass compilation support)
• Symbol table built for ambiguous parsing
• Partial parses, recursive parsing, parsing starting with any non-terminal
• Whitespace can be specified as a subgrammar
• External (C call interface) tokenizers and terminal scanners
• Good asymptotic efficiency
• Comes with ANSI-C, Python and Verilog grammars
• Comes with full source
• Portable C for easy compilation and linking
• BSD licence, so you can include it in your application without worrying about licensing

Example Grammars

• ANSI-C
• Python
• Verilog

Documentation

• Man page for parser generator
• Manual
• FAQ

Public Headers

• dparse.h - main parser data structures and functions
• dparse_tables.h - parse tables data structures
• dsymtab.h - optional symbol table

Building

• To build: gmake -- only available with source code package
• To test: gmake test -- only available with source code package
• To install: gmake install -- binary or source code packages

For python support: cd python; gmake install

Makefile Options

• D_USE_GC: set to 1 to use the Boehm garbage collector
• D_DEBUG: set to 1 to compile with debugging support (-g)
• D_OPTIMIZE: set to 1 to compile with optimizations (-O3)
• D_PROFILE: set to 1 to compile with profiling support (-pg)
• D_LEAK_DETECT: set to 1 to compile with memory leak detection (-lleak)
• D_USE_FREELISTS: set to 1 to use free lists instead of straign free/malloc (defaults to 1)

Contact

Contact the author: jplevyak at gmail