postcard VS rust-peg

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.

And some related parser tools: - https://github.com/kevinmehall/rust-peg - https://github.com/pest-parser/pest - https://github.com/lalrpop/lalrpop

Rust is a very nice langage for implementing compilers, and has a nice ecosystem for it (logos, rust-peg, lalrpop, astmaker -- this one is mine --, etc...).

My peg crate is a parser generator that supports arbitrary token types as input. See https://github.com/kevinmehall/rust-peg/blob/master/tests/run-pass/tokens.rs for an example.

The one rust parser-generator I used is PEG

The two parser generators that I am aware of are lalrpop and PEG. There both great, and have seen some use by languages that have been written in Rust.

rust-peg

I wanted to create a parser for Apertium Stream. In 2014, I used Whittle in Ruby. If this year were 2001, I would use Lex/Yacc. Anyway, this year is 2021. I wanted to create this parser in Rust. I tried to find what is similar to Lex/Yacc. I found Rust-Peg. I found a link to Nom from Rust-Peg's document. My first impression was Nom example is easy to read. At least, its document claimed Nom is fast.

The peg crate has a resolved issue about this.

I don't really know that much about parsing and grammars, other than what I've learned about regular languages and expressions and context-free languages in a standard Theory of Comp course from my university. I basically just learned peg by reading the Wikipedia article on PEGs, reading the crate documentation to understand the syntax, and then looking at some of the peg examples on their GitHub to understand how it works in practice.