jamesmcnamara/shades

Performance of TypeScript overloads

hasparus opened this issue · 17 comments

hasparus commented

First of all, I wanted to say that shades is really cool and has very nice public API.

You're generating overloads with PureScript and that's pretty awesome in my opinion, but my VSCode seems to disagree. Tooltips and code completion start to get laggy.

Did you have any trouble with text editors with generated typings?
I'm thinking about generating overloads with smaller depth and using patch-package to substitute generated typings as a workaround.

jamesmcnamara commented

I'm glad you like it!

I'm worried to hear that; I was very worried the performance would sputter when I was working on it, but I didn't have any problems on my dinky old MacBook Air so I figured it was fine. Could it possibly be something else? If you sent me a minimal repo that's laggy for you, I'd take a look at it.

However if you do want to have a smaller depth file, then you should just have to

cd node_modules/shades/lens-gen;
npx bower install;
npx pulp main -- -n=N

N=4 would probably be a good depth; it's only 340 overloads per function as opposed to 5,460.

If more people want this and 4 turns out to be a good number, I could include that shorter file in the repo so you'd have the option to do:

import { get, mod, matching } from 'shades/tiny'
hasparus commented

I didn't notice any problems in an empty TS project with shades as the only dependency, but I managed to get stuck on loading a few times just pasting examples from README into a fresh NextJS project.

Here's the link -- https://github.com/hasparus/repro--shades-ts-lag/blob/master/pages/index.tsx.

image

image

jamesmcnamara commented

Weird. After a brief boot up, I saw very fast performance and accurate bug-checking on everything, even on this dinky old laptop.

The only thing I did change was switching on

  "strict": true

in the tsconfig.json. A bunch of things behave badly without that, so maybe that could help?

If not, try the depth 4 typings and see if that fixes it. We can take it from there.

hasparus commented
hasparus commented
jamesmcnamara commented

Sounds good :)

hath995 commented

I'm running into this problem as well.

jamesmcnamara commented

@hath995 I would encourage you to try creating a minimal repro that has lag. Like I say; I run this on a 6 year old MacBook Air without any trouble, so my instinct is that there is something else at play.

But I am open to creating a smaller set of typings that can be used for limited environments.

hath995 commented

I am using a 2018 macbook pro so it would seem like it should be fast enough, but it basically locks up vs-code while it thinks about the types. I used your suggestion about and replaced my file with npx pulp main -- -n=4 and it became tolerable.

jamesmcnamara commented

Have you tried starting a new project, installing shades, and trying it there?

You could just toss this into a file in a new project and test it's speed:

import { get, set, mod } from 'shades'

interface Post {
  title: string;
  description: string;
  likes: number;
}

interface User {
  name: string;
  posts: Post[];
  goldMember: boolean;
  friends: User[];
  bestFriend?: User;
}

declare const users: User[];
declare const user: User;
declare const byName: { [name: string]: User };
hath995 commented

Seems ok using that example you pasted. In tsconfig turned on libs ["dom","es2017","esnext"] and then it seemed to slow down the type resolution quite a bit, probably like 5 seconds before it resolved that something was a user.

let test  = set("posts", 0, "likes")(2)(user);
jamesmcnamara commented

Do you have "strict": true on?

hath995 commented

It is, yes.

jamesmcnamara commented

Alright. I will try to publish a version of this library with smaller bindings ASAP, and I'll keep you posted.

ptpaterson commented

I think Variadic Tuple Types coming in TS4 should help, or maybe be able to eliminate all the overloading.

  • 👍2
premshree commented

I love the shades API! I don’t have anything extremely useful to add, but just wanted to +1 that I also noticed my IDE and MacBook Pro (2018, 16G RAM) struggled with inferring types the moment I added some shades-based code - I’m using TypeScript 4.6 with strict mode. I’ll update here if I can narrow it down to a reproducible set for you. Unfortunately I haven’t been able to work with it long enough before my IDE runs out of memory!

ptpaterson commented

For the record, variadic tuple types was not the miracle I was hoping for 😬. One of the reasons why shades is so awesome IMO is how flexible it is. Encoding the flexibility into the type system is clearly not straightforward. Or rather, I suppose it is straightforward, also just extremely verbose.