Consider making it available for other go projects to use as library

[thers]

It would be great if we could reuse parts of it. In particular I'd like to reuse the parser part.

[evanw]

The parser in esbuild is very specific to this project and contains many things that are only needed for later passes inside esbuild. The API of the parser is intended to be internal only. This lets me iterate on it and adapt it to whatever esbuild needs. Making the parser reusable would make it harder for me to improve esbuild.

I don't think there's anything particularly special about esbuild's parser. The big speed up that esbuild achieves is more due to the rest of the pipeline that does bundling, minifying, and source map generation much faster than other bundlers. I'm sure there are other parsers for JavaScript written Go that are just as fast while also having a stable API. If not, someone could fork the parser in this project and create a stable API out of it, but that's a separate project than this one.