Crate roam_macros_parse 

Parser grammar for roam RPC service trait definitions.

This Is Just a Grammar

This crate contains only the unsynn grammar for parsing Rust trait definitions that define roam RPC services. It does not:

• Generate any code
• Perform validation
• Know anything about roam’s wire protocol
• Have opinions about how services should be implemented

It simply parses syntax like:

pub trait Calculator {
    /// Add two numbers.
    async fn add(&self, a: i32, b: i32) -> i32;
}

…and produces an AST (ServiceTrait) that downstream crates can inspect.

Why a Separate Crate?

The grammar is extracted into its own crate so that:

1. It can be tested independently — We use datatest-stable + insta for snapshot testing the parsed AST, which isn’t possible in a proc-macro crate.

2. It’s reusable — Other tools (linters, documentation generators, IDE plugins) can parse service definitions without pulling in proc-macro dependencies.

3. Separation of concerns — The grammar is pure parsing; roam-macros handles the proc-macro machinery; roam-codegen handles actual code generation.

The Bigger Picture

roam-macros-parse     roam-macros              roam-codegen
┌──────────────┐     ┌──────────────┐         ┌──────────────┐
│              │     │              │         │              │
│  unsynn      │────▶│  #[service]  │────────▶│  build.rs    │
│  grammar     │     │  proc macro  │         │  code gen    │
│              │     │              │         │              │
└──────────────┘     └──────────────┘         └──────────────┘
   just parsing         emit metadata          Rust, TS, Go...

Structs

AngleTokenTree

Parses either a TokenTree or <...> grouping.

DocAttribute

GenericParams

KAsync

Matches: async,

KDoc

Matches: doc,

KFn

Matches: fn,

KMut

Matches: mut,

KPub

Matches: pub,

KSelfKw

Matches: self,

KTrait

Matches: trait,

KWhere

Matches: where,

Lifetime

MethodParam

MethodParams

ParseError

Error type for parsing.

PathWithGenerics

RawAttribute

RefSelf

ReturnType

ServiceMethod

ServiceTrait

TypePath

TypeRef

TypeTuple

WhereClause

Enums

GenericArgument

Type

Visibility

Traits

ToTokens

unsynn defines its own ToTokens trait to be able to implement it for std container types. This is similar to the ToTokens from the quote crate but adds some extra methods and is implemented for more types. Moreover the to_token_iter() method is the main entry point for crating an iterator that can be used for parsing.

Functions

method_ok_and_err_types

Extract Ok and Err types from a return type. Returns (ok_type, Some(err_type)) for Result<T, E>, or (type, None) otherwise.

parse_trait

Parse a trait definition from a token stream.