Smallest possible build

[occasionallydavid]

Hey there,

Is the min.js build on unpkg.com the smallest possible build? I notice it includes all the validation code. Has anyone tried a build configuration omitting that code entirely? With Brotli the client footprint is about 30.5kb using the unpkg build

[bd82]

Is the min.js build on unpkg.com the smallest possible build?

Probably not.

1. The bundle contains everything, including features that may not be relevant for everyone, e.g:

• auto-complete.
• CST Visitor.
• CST signatures generation.

So its possible if someone performs their own bundling with a smart bundler (tree-shaking) that a smaller bundle would be created per specific use case. I believe lodash have implemented a way to import specific properties to help bundling tools produce a smaller
bundle, perhaps something like this could be implemented...

• https://lodash.com/per-method-packages

I notice it includes all the validation code. Has anyone tried a build configuration omitting that code entirely?

That is a bit tricky, Chevrotain performs the validations during Parser initialization as there is no grammar generation phase.
Which is why its important from a performance point of view to re-use the same instance.

• https://chevrotain.io/docs/guide/performance.html#using-a-singleton-parser

The reasons it becomes tricky is that some validations can be optionally skipped, e.g: run those only during local testing, but no in production, but this is a dynamic option and the bundlers use static analysis.

With Brotli the client footprint is about 30.5kb using the unpkg build

What is Brotli ? is it an alternative and more aggressive bundling tool?

[occasionallydavid]

Thanks so much for quick a detailed response.

Brotli is a modern compression algorithm supported by recent browsers. I think unpkg is already using it, but not with the maximum compression setting.

I will give a custom build a shot once my grammar is closer to ready. Seems there is quite a lot that can be omitted with a little effort. Thanks again

[bd82]

Thanks for the info on Brotli.

I will give a custom build a shot once my grammar is closer to ready

Please share if/when you have additional info/insights. 👍

I am interested to understand, in what scenario does it it important if a library is 30.5k compressed or 15k compressed?
Are we talking about a website that needs to work quickly on a 2G / Analog connection out in the wilderness? 🌴

[occasionallydavid]

Are we talking about a website that needs to work quickly on a 2G / Analog connection out in the wilderness?

Exactly this

[bd82]

How complex is your grammar and how complex are the features you need to implement with it? (e.g error recovery / auto-complete) ?
If you only need:

• A straight forward parser that stops on the first error, without error recovery.
• No editor related functionality (formatter / auto-complete / ...)
• And the grammar itself is not too complex

you could consider rolling out your own hand crafted parser.

• Example hand-crafted RegExp Parser : https://github.com/bd82/regexp-to-ast/blob/master/lib/regexp-to-ast.js

On the other hand if your use case is complex enough to gain significant benefits from Chevrotain's features
It might make more sense to invest in a custom build or even contribute capabilities related to smaller bundle to Chevrotain itself.
Just keep in mind the option to write your own parser by hand...

[bd82]

I started #1697 to track this