KDevelop-PG-Qt is a parser generator written in readable source-code and generating readable source-code. Its syntax was inspirated by AntLR. It implements the visitor-pattern and uses the Qt library. That is why it is ideal to be used in Qt-/KDE-based applications like KDevelop.
You can find an introduction at KDE-Techbase:
See <techbase.kde.org/Development/KDevelop-PG-Qt_Development_Guide">http://techbase.kde.org/Development/KDevelop-PG-Qt_Development_Guide> for basic information
about KDevelop-PG-Qt-Development and ideas for future you could implement.