Grammatica Features

Existing Features

This is a summary of the features currently present in Grammatica.

Standard grammar syntax definitions
The grammar files define the tokens with regular expressions, and the syntax with plain EBNF. It is also possible to specify tokens as strings, avoiding escaping of any special regular expression characters.
Clean & reusable grammar files
No parser source code is present in the grammar files, providing a cleaner separation between the grammar and the parser. This means that the grammar files can be reused by other applications.
Support for LL(k) grammars
LL grammars with various number of look-ahead tokens are supported. There is no need to declare the number of look-ahead tokens needed.
Detailed error messages for generated parsers
Messages generated when an error is found always describe the problem with all required details. In particular, the list of expected tokens is always presented.
Automatic error recovery
Error recovery is always attempted by the parsers generated, without any changes needed in the grammar files. This makes generated parsers much more usable.
Analysis though callbacks or syntax trees
It is possible to parse the grammar either through callbacks or by traversing the syntax tree. When using callbacks, the syntax tree creation can be avoided.
Parser generation for C# and Java
Both C# and Java parsers can be generated from the same grammar file. Both parsers behave in the same way and have the same feature set, including the regular expression support.
Full Unicode and regular expression support
The generated parsers use the Java or .NET platform support for Unicode and regular expressions to provide optimal integration and compatibility.
Readable and commented output source code
The source code generated is fully readable, being correctly indented and commented.
Run-time parser creation
With the Grammatica parser libraries, an ad-hoc parser can be created at run-time without the need for generating source code. This can be used for easier debugging of grammars, or for creating parsers interactively.
Integration with Apache Ant
Apache Ant tasks are available, integrating Grammatica with the standard build tool for Java developers.

Upcoming Features

No commitment has been made regarding which new features will be present in future releases. See the TODO-list for a the currently known future improvements.