GF 3.0

GF Version 3.0 is a major revision of GF. The source language is a superset of the language in 2.9, which means backward compatibility. But the target languages, the compiler implementation, and the functionalities (e.g. the shell) have undergone radical changes.

New features

Here is a summary of the main novelties visible to the user:

• Size: the source code and the executable binary size have gone down to about the half of 2.9.
• Portability: the new back end format PGF (Portable Grammar Format) is much simpler than the old GFC format, and therefore easier to port to new platforms.
• Multilingual web page support: as an example of portability, GF 3.0 provides a compiler from PGF to JavaScript. There are also JavaScript libraries for creating translators and syntax editors as client-side web applications.
• Incremental parsing: there is a possibility of word completion when input strings are sent to the parser.
• Application programmer's interfaces: both source-GF and PGF formats, the shell, and the compiler are accessible via high-level APIs.
• Resource library version 1.4: more coverage, more languages; some of the new GF language features are exploited.
• Uniform character encoding: UTF8 in generated files, user-definable in source files

Non-supported features

There are some features of GF 2.9 that will not work in the 3.0 beta release.

• Java Editor GUI: we now see the JavaScript editor as the main form of syntax editing.
• Pre-module multi-file grammar format: the grammar format of GF before version 2.0 is still not yet supported.
• Context-free and EBNF input grammar formats.
• Probabilistic GF grammars.
• Some output formats: LBNF.
• Some GF shell commands: while the main ones will be supported with their familiar syntax and options, some old commands have not been included. The GF shell command help -changes gives the actual list.

Users who want to have these features are welcome to contact us, and even more welcome to contribute code that restores them!

GF language extensions

Operations for defining patterns.

Inheritance of overload groups.