More flexible precedence parsing

[tertsdiepraam]

The precedence and associativity of operators is currently baked into the structure of the parser. I'd love to refactor this to a more flexible system which defines the precedence in a data structure.

Examples:

• https://github.com/lace-language/lace/blob/main/crates/lace-bin/src/parser/precedence.rs
• https://github.com/nushell/new-nu-parser/blob/7b63219f0514062a772c42a7a8a145a217ae4887/src/parser.rs#L258

[LevitatingBusinessMan]

You might find crafting interpreters section on Pratt Parsing interesting:

https://craftinginterpreters.com/compiling-expressions.html#a-pratt-parser

This is a (very rudimentary) Rust implementation: https://github.com/LevitatingBusinessMan/loxidation/blob/master/src/compiler/rules.rs

[tertsdiepraam]

That's a good hint! I also came across these articles recently:

• https://matklad.github.io/2020/04/13/simple-but-powerful-pratt-parsing.html
• https://matklad.github.io/2025/12/28/parsing-advances.html

More error resilient parsing would be awesome to have as well, but we can take this in stages.

[tertsdiepraam]

By the way, feel free to take a stab at this @LevitatingBusinessMan. I won't get to this until the next version is released. It should all be fairly standard parsing. The strangest requirement in the current parser (that I'd like to keep) is that && cannot be chained with || because the precedence is undefined.