poletaevvlad / larkeditor

An editor for EBNF grammars, used by Lark – parsing library for Python

lark-editor

lark-editor is a GTK-based development tool for creating and editing context-free grammar files used by the Lark parsing library. It allows users to see how their rules affect the abstract syntax tree generation without the need to terminate and rerun their applications.

Features of lark-editor include:

• syntax and error highlighting;
• autocompletion of rule and terminal names;
• automatic generation of an AST based on user-defined grammar and text;
• an ability to configure the parser (Earley, LARL or CYK) and starting rule;
• saving and loading grammar and text to/from a file.

There are some limitations of this software. As it has been developed as a tool to be used during the development of another project, I have not written any automatic tests due to time constraints. The dark version of the UI has not been implemented yet.

Installation

lark-editor requires Python 3.6 or newer. Older versions of the interpreter are not supported.

lark-editor has some dependencies that are not as straightforward to install as one might hope. First of all, it depends on GTK and its python bindings --- pygobject. Fortunately, it can be installed via package managers of some popular Linux distributions. For the instructions for installing pygobject and its transient dependencies, please refer to the installation guide.

Another dependency is GtkSourceView. You can install it from the tarball or via your system's package manager.

Although it is theoretically possible to run lark-editor on Windows OS, it has not been tested.

After native dependencies are resolved, you may install lark-editor globally or in a python virtual environment by cloning this repository and running setup.py install:

git clone https://github.com/poletaevvlad/larkeditor
cd larkeditor
python3 setup.py install

Note: If you install lark-editor into a virtual environment, you need to first install pygobject using pip. It will not work without native libraries.

pip install pygobject

Usage

After installation, you may run lark-editor by using a 'gui_script' created by setup.py or by running the module larkeditor. Either one of the following options should work:

lark-editor [filename]

or

python3 -m larkeditor

License

This application is licensed under BSD 2-clause license. You can find the text of the license in the LICENSE file.

Several third-party open source licenses are used. The licensing information can be found in LICENSE-3RD-PARTY file.