golem-rust-macro 2.0.0-dev.3

Golem Rust tooling library that facilitates writing Golem backends in Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47

// Copyright 2024-2026 Golem Cloud
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use crate::recursion::is_recursive;
use crate::value;
use proc_macro::TokenStream;
use proc_macro2::Ident;
use quote::quote;
use syn::{DeriveInput, parse_macro_input};

pub fn derive_schema(input: TokenStream, golem_rust_crate_ident: &Ident) -> TokenStream {
    let ast = parse_macro_input!(input as DeriveInput);

    let is_recursive = is_recursive(&ast);

    if is_recursive {
        return syn::Error::new_spanned(
            &ast.ident,
            format!("Cannot derive `Schema` for recursive type `{}`\n\
            Recursive types are not supported by `Schema` yet\n\
            Help: Avoid direct recursion in this type (e.g. using index-based node lists) and then derive `Schema`", ast.ident
        )).to_compile_error().into();
    }

    let into_value_tokens: proc_macro2::TokenStream =
        value::derive_into_value(&ast, golem_rust_crate_ident).into();

    let from_value_tokens: proc_macro2::TokenStream =
        value::derive_from_value_and_type(&ast, golem_rust_crate_ident).into();

    quote! {
        #into_value_tokens
        #from_value_tokens
    }
    .into()
}