ZephyrASDL was created in February of 2024 by Chubak Bidpaa, an implementation of Appel, Wang et al's Zephyr Abstract Syntax Description Language describe in 1997 paper of the same name. ASDL brings the robust typing system of ML-like languages to any language with less forgiving type syntax.
Known Variants:
- pyasdl: A library for Python which implements a parser for ASDL. This library is used in CPython's source code to generate the language's tree.
- Original implementation by the authors: This implementation targets more languages, such as SML. But It's just too outdated, and clunky to build. Worse is, it is bootstrapped upon itself, so building it is almost impossible.
The first release predates the creation of this document. The first release was rife with issues.
- In revision 2, besides major improvements, linked lists were added --- both to the main code, and the generated code.
- More built-in types were added in revision 2.
Major improvements were made to the revision 3 of ZephyrASDL, the include:
- Better error reporting during lexical analysis
- A lot more built-in types
- Improvements to variant types
- Generating
appendanddumpfunctions for sequential items
These are just a few features added to rev. 3; please check out the git logs (git log) for a detailed list of changes.
Several features were added. Chiefly amongst them is, the generation of append/free and other such capabilities for sequential fields in product types. Previously, they were not present.
- Functions for appending to product type chain added.
- Added
p->next = NULL;to all constructors.
- Added symbols declaration file via
-sflag - Added header guards for both locators and the symbols file
- Added
tyspecssection for defining types in.