postcard VS JSMN

I've been enjoying postcard as a lightweight efficient binary serialization.

That said, postcard is not a self describing format (so everyone needs the same schema, no changes allowed), but I do have a tracking issue open for ways to handle this in the future.

For example, look at the Postcard serializer for inspiration.

Serde should be no_std, I have used it embedded with crates such as postcard. You can see how postcard disables default features of serde here : https://github.com/jamesmunns/postcard/blob/main/Cargo.toml

Another option that may work for some is SerDe on rust. You just write a struct with the fields you want #[derive(Serialize, Deserialize)] above it, and if codegens the functions to deserialize that struct from JSON and serialize it back. Example looks like this https://docs.rs/serde_json/latest/serde_json/#creating-json-by-serializing-data-structures (but you have to use serde-json-core if you don’t have an allocator). Can also easily reserialize to something small like postcard that’s meant for embedded storage.

https://github.com/jamesmunns/postcard

postcard seems like it would be particularly strong for the wasm use case as it produces small messages that are light in memory.

Like how https://github.com/zserge/jsmn works. I thought it would be neat to have such as parser for https://github.com/vshymanskyy/muon

One more JSON implementation using this approach is https://github.com/zserge/jsmn.

Yep! I'm using JSMN (https://github.com/zserge/jsmn), which is a streaming parser that visits each token sequentially, so there's only one copy of each JSON response in memory. I also avoid allocating new intermediate memory whenever possible; for example, to unescape backslashes in the JSON strings, I use a destructive loop that moves the non-backslash characters forward in memory, and truncates the string by moving the null terminator earlier in the string. Not something I'd imagine doing in most environments today, but as you said, it saves a bit of space at the expense of CPU time :)

  void DestructivelyUnescapeStr(LPSTR lpInput) {

After reviewing several options, I’ve settled on plain old JSON. For parsing, I use https://github.com/zserge/jsmn. For serialization I use https://github.com/rdpoor/jems (disclaimer: I wrote the latter, but others use it as well).

As mentioned here, it appears that tiny-json is a parser, not a serializer. If you're looking for parsers, I've been very happy with jsmn.

Very small, 4-5 fields but I'm still going to write in binary because I'm trying to reduce dependencies and https://github.com/zserge/jsmn looks like good fit but jsmn only does parsing which I need for parsing some Oauth json data and config.json file. I will be able to dump the state struct in a state.bin file and read it later for comparing it with system time. Not having to write in text fits well for this particular use case. Benefits: Reduced dependencies and almost cost less decoding of the state struct(which the user will never see).

This is my very straight-forward implementation that came to be from the lack of JSON encoding in jsmn: