I've made some web apps, and I needed to parse large (>20M) json files.
On Android JSON.parse does the job pretty well, but on iOS, well, it just crashes with JSON files over 500kb.
I've resorted to using a plain javascript parser (LosslessJSON) wich works pretty well.
I've forked and edited this library so that it would use normal numbers (instead of LosslessNumbers)
as I didn't need that feature which is slower and uses more memory (my fork is called JsonLib).
Now, I've exported a JSON parser from the Rust library serde_json and compiled it to wams.
It's faster (30-50% faster) than LosslessJSON, but slower (8 times slower) than native JSON.parse.
I think most of the time is spent on transferring data between wasm and js, idk, please help.
Just copy pkg/rs_json_bg.wasm and pkg/json_rs.js in a folder.
Then, do this:
<head>
<script src="json_rs.js"></script>
<script>
wasm_bindgen('json_rs_bg.wasm').then(() => {
window.RustJson = wasm_bindgen
})
</script>
</head>There are actually two parse functions: parse and _parse, the first one uses serde_json, the second one uses serde_json_wasm which should be better for constrained environments, but it does not work. Maybe one day it will.