Java package sources implementing the hak.language.syntax API
The architecture of this code is described and discussed in the article: “An Abstract, Reusable, and Extensible Programming Language Design Architecture” in: Essays dedicated to Peter Buneman — In Search of Elegance in the Theory and Practice of Computation (Edinburgh, UK), Val Tannen, Limsoon Wong, Leonid Libkin, Wenfei Fan, Wang-Chiew Tan, and Michael Fourman (Eds.), Lecture Notes in Computer Science Volume 8000, pp. 112–166. October 27–28, 2013. https://www.researchgate.net/publication/259812394_An_Abstract_Reusable_and_Extensible_Programming_Language_Design_Architecture