Parser construction library with great error reporting in Ruby

 Parslet makes developing complex parsers easy. It does so by
 .
 * providing the best error reporting possible
 * not generating reams of code for you to debug
 .
 Parslet takes the long way around to make your job easier. It allows for
 incremental language construction. Often, you start out small, implementing
 the atoms of your language first; _parslet_ takes pride in making this
 possible.