ruma_events_macros/
lib.rs

1#![doc(html_favicon_url = "https://www.ruma.io/favicon.ico")]
2#![doc(html_logo_url = "https://www.ruma.io/images/logo.png")]
3//! A procedural macro for generating [ruma-events] events.
4//!
5//! See the documentation for the individual macros for usage details.
6//!
7//! [ruma-events]: https://github.com/ruma/ruma/tree/main/ruma-events
8
9#![warn(missing_docs)]
10
11use event_parse::EventEnumInput;
12use proc_macro::TokenStream;
13use proc_macro2 as pm2;
14use proc_macro_crate::{crate_name, FoundCrate};
15use quote::{format_ident, quote};
16use syn::{parse_macro_input, DeriveInput};
17
18use self::{
19    event::expand_event,
20    event_content::expand_event_content,
21    event_enum::{expand_event_enums, expand_from_impls_derived},
22    event_type::expand_event_type_enum,
23};
24
25mod event;
26mod event_content;
27mod event_enum;
28mod event_parse;
29mod event_type;
30mod util;
31
32/// Generates an enum to represent the various Matrix event types.
33///
34/// This macro also implements the necessary traits for the type to serialize and deserialize
35/// itself.
36///
37/// # Examples
38///
39/// ```ignore
40/// # // HACK: This is "ignore" because of cyclical dependency drama.
41/// use ruma_events_macros::event_enum;
42///
43/// event_enum! {
44///     enum ToDevice {
45///         "m.any.event",
46///         "m.other.event",
47///     }
48///
49///     enum State {
50///         "m.more.events",
51///         "m.different.event",
52///     }
53/// }
54/// ```
55/// (The enum name has to be a valid identifier for `<EventKind as Parse>::parse`)
56//// TODO: Change above (`<EventKind as Parse>::parse`) to [] after fully qualified syntax is
57//// supported:  https://github.com/rust-lang/rust/issues/74563
58#[proc_macro]
59pub fn event_enum(input: TokenStream) -> TokenStream {
60    let ruma_events = import_ruma_events();
61
62    let event_enum_input = syn::parse_macro_input!(input as EventEnumInput);
63    let enums = event_enum_input
64        .enums
65        .iter()
66        .map(expand_event_enums)
67        .collect::<syn::Result<pm2::TokenStream>>();
68    let event_types = expand_event_type_enum(event_enum_input, ruma_events);
69    event_types
70        .and_then(|types| {
71            enums.map(|mut enums| {
72                enums.extend(types);
73                enums
74            })
75        })
76        .unwrap_or_else(syn::Error::into_compile_error)
77        .into()
78}
79
80/// Generates an implementation of `ruma_events::EventContent`.
81#[proc_macro_derive(EventContent, attributes(ruma_event))]
82pub fn derive_event_content(input: TokenStream) -> TokenStream {
83    let ruma_events = import_ruma_events();
84    let input = parse_macro_input!(input as DeriveInput);
85
86    expand_event_content(&input, &ruma_events).unwrap_or_else(syn::Error::into_compile_error).into()
87}
88
89/// Generates implementations needed to serialize and deserialize Matrix events.
90#[proc_macro_derive(Event, attributes(ruma_event))]
91pub fn derive_event(input: TokenStream) -> TokenStream {
92    let input = parse_macro_input!(input as DeriveInput);
93    expand_event(input).unwrap_or_else(syn::Error::into_compile_error).into()
94}
95
96pub(crate) fn import_ruma_events() -> pm2::TokenStream {
97    if let Ok(FoundCrate::Name(name)) = crate_name("ruma-events") {
98        let import = format_ident!("{}", name);
99        quote! { ::#import }
100    } else if let Ok(FoundCrate::Name(name)) = crate_name("ruma") {
101        let import = format_ident!("{}", name);
102        quote! { ::#import::events }
103    } else if let Ok(FoundCrate::Name(name)) = crate_name("matrix-sdk") {
104        let import = format_ident!("{}", name);
105        quote! { ::#import::ruma::events }
106    } else if let Ok(FoundCrate::Name(name)) = crate_name("matrix-sdk-appservice") {
107        let import = format_ident!("{}", name);
108        quote! { ::#import::ruma::events }
109    } else {
110        quote! { ::ruma_events }
111    }
112}
113
114/// Generates `From` implementations for event enums.
115#[proc_macro_derive(EventEnumFromEvent)]
116pub fn derive_from_event_to_enum(input: TokenStream) -> TokenStream {
117    let input = parse_macro_input!(input as DeriveInput);
118    expand_from_impls_derived(input).into()
119}
ruma_events_macros/lib.rs

ruma_events_macros/
lib.rs
