Piraha: A simplified grammar parser for component little languages

Software codes in scientific computing often implement their own little languages for expressing configuration data, interface definitions, and runtime parameters. Such languages are of particular importance for component-based frameworks. These languages can initially be somewhat ad-hoc and then expand organically. We describe how parsing expression grammars (PEG) can provide the capabilities for scientific application developers to easily construct appropriate parsers which will enable improved and more robust little languages. We show how a little language parser could be used with the Cactus Configuration Language in the Cactus Framework.