LLOOP Features

Generator

• GNU Graphical Front-end for eased configuration and running through simple GUIs. Support for sub-projects
• Explicit configuration through file (gspc.cfg) or/and command line remains possible
• Persistency and overloading of generation parameters: when generator is invoked on command line without arguments, it uses parameters of last execution. Additional arguments either overload previous stored parameters or complete them
• Automatic file management: Useless files are cleaned up and only files that change from a generation to another are actually updated
• All generation parameters inclusive build/makefile project configurable through GUI
• main.cpp is never overwritten

Generated C++ and Makefiles

C++

• Cross-platform code conforming to ISO C++98 C99. Tried and tested with following compilers:
• gcc 4.1.0, 3.4.5 and 2.9x (Red Hat Linux and Fedora Linux)
• Visual C++ 6.0 (Windows 2000 and XP)
• Visual C++ 4.0 (with namespace disabling)
• Relies on the C++ standard library. Version of the C++ streams can be configured, depending on target development environment. Differences between I/O stream versions are well explained in the MSDN for example.
• Uses namespaces (name of the .gsp file without extension). Namespacing can be disabled.

Makefiles

• Standard Makefiles for UNIX (.mak extension) and Windows (.nmak). Tried and tested with GNU Make and NMake under Windows
• Full support of dependencies between generated source code files
• Customisable cross-platform build/makefile project through GUI

Parsers

Overall features

• Self-dependent descent parsers, also often referred to under the technical term LL parsers,
• Reversely, any parsed object can be expanded back in order to re-constitute or modify the original input, with preserving of new line and space chars.
• Configurable case-sensitiveness
• Includes Pre-processing
• Processing of input regardless of source (file, socket, pipe, standard input...)
• Built-in self-test platform for unit testing and automatic non-regression testing
• Each non-terminal, each token and each pre-processor is mapped to a class. A separate Parser class is generated and used to parse an input according to the grammar
• The generated code implements the "Visitor" design pattern which permits to "visit" the hierarchy of objects obtained from the parsing, and thereby to implement post-processors. The above-mentioned expanding function relies on it, as well as the backtracing function

• Shows cursor to the precise start position of syntax error,
• Context lines within source input, with configurable scope,
• Breaking error function to make the parsing stop immediately with a failure,
• Non-breaking / contentwise error functions,
• Warning messages
• Backtracing of parsed rules and symbols. Useful for debugging parse errors
• Advanced services provided for each symbol. See the Generated Code API documentation

See also this example

• No support for backtracking (do not confuse with backtracing),
• No indirect infinite recursion check: It is possible to write grammars such that parsing falls into an infinite loop when using empty rules,
• References to symbols ($... and #...) in reduction code are not checked for consistency. Using an invalid reference will simply result in a compilation error of the generated code,

Tokens and Pre-processors

Click here

This file is part of the LLOOP Reversible Object-Oriented Parser Generator. Copyright (c) 2005-2006 Michel MEHL, France. All rights reserved. LLOOP is distributed by the company ERSA SaRL.