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feldera_macros/
lib.rs

1//! Procedural macros for Feldera tuple types and utility traits.
2//!
3//! The `declare_tuple!` macro decides which layout to use based on tuple size
4//! and the active storage format rules.
5
6use proc_macro::TokenStream;
7use quote::quote;
8use syn::{parse_macro_input, DeriveInput};
9
10mod tuples;
11
12/// Parses input of the form: `declare_tuple!(Tup1<T0>);`
13/// and generates dbsp tuple structs.
14#[proc_macro]
15pub fn declare_tuple(input: TokenStream) -> TokenStream {
16    let tuple = parse_macro_input!(input as tuples::TupleDef);
17    let expanded = tuples::declare_tuple_impl(tuple);
18    if std::env::var_os("FELDERA_DEV_MACROS_DUMP").is_some() {
19        let parsed_file: syn::File = syn::parse2(expanded.clone()).expect("Failed to parse output");
20        let formatted = prettyplease::unparse(&parsed_file);
21        eprintln!("{}", formatted);
22    }
23
24    expanded.into()
25}
26
27#[proc_macro_derive(IsNone)]
28pub fn derive_not_none(item: TokenStream) -> TokenStream {
29    let input = parse_macro_input!(item as DeriveInput);
30
31    let ident = input.ident;
32    let generics = input.generics;
33    let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
34
35    let expanded = quote! {
36        impl #impl_generics ::dbsp::utils::IsNone for #ident #ty_generics #where_clause {
37            type Inner = Self;
38
39            #[inline]
40            fn is_none(&self) -> bool {
41                false
42            }
43
44            #[inline]
45            fn unwrap_or_self(&self) -> &Self::Inner {
46                self
47            }
48
49            #[inline]
50            fn from_inner(inner: Self::Inner) -> Self {
51                inner
52            }
53        }
54
55        impl #impl_generics ::dbsp::utils::SupportsRoaring for #ident #ty_generics #where_clause {}
56    };
57
58    TokenStream::from(expanded)
59}