tao-data-csharp VS lua-patterns

Still early, but here's my baby I hope can improve things:

website with grammar spec: https://tree-annotation.org/

prototype of a JSON/YAML alternative for JS: https://github.com/tree-annotation/tao-data-js

same thing, even less finished for C#: https://github.com/tree-annotation/tao-data-csharp

working on it constantly, more to come soon

If you want automatic built-in string validation, one option that seems particularly interesting is to use a variant of Lua patterns, which are weaker and easier to understand than regular expressions, but still provide a significant degree of "sanity" for something like an email. The original version works on bytes and not runes, but you could simply write a parser that works on runes instead, and the pattern-matching code is just 400 old and battle-tested lines of C89.

Lua patterns have also shown up in other places, such as BSD's httpd, and an implementation for Rust:

https://www.gsp.com/cgi-bin/man.cgi?section=7&topic=PATTERNS

https://github.com/stevedonovan/lua-patterns

http://lua-users.org/wiki/PatternsTutorial