What’s an example complex generic? If you have one, that is, I’m curious what kinds of things people do with types. I’m a fan of using types, myself. Thanks in advance.
Couldn't find a proper example on the spot in an open source project.
[1] https://github.com/sindresorhus/type-fest/blob/main/source/g...
That's ninety lines of type constraints.
But things I encounter in the regular non-library world are usually recursive types that have specific constraints. A couple years ago I had my first foray into typescript generics, and was so stumped that I actually gave up. I was trying to map the type of one nested object to another. This[2] is the stackoverflow post from the legendary jcalz that saved me! Check jcalz's link to the TS playground
[1]https://github.com/kysely-org/kysely/blob/master/src/query-b... [2]https://stackoverflow.com/questions/72461962/is-it-possible-...
eg https://github.com/jakearchibald/idb
Honestly most complicated types boil down to a handful of concepts (mapped types, conditionals, recursion) with a few tricks for working around sharp corners (deferring evaluation for performance, controlling whether a union distributes).
I've even seen someone solve 8-queens in types using a formal grammar but no clue how that worked. Speaking of, if anyone else has other examples of defining a grammar or ast in typescript, I'd love to see it.
Honestly most complicated types boil down to a handful of concepts (mapped types, conditionals, recursion) with a few tricks for working around sharp corners (deferring evaluation for performance, controlling whether a union distributes).
I've even seen someone solve 8-queens in types using a formal grammar but no clue how that worked. Speaking of, if anyone else has other examples of defining a grammar or ast in typescript, I'd love to see it.