hecs_macros/
lib.rs

1extern crate proc_macro;
2
3mod bundle;
4mod bundle_clone;
5mod query;
6
7pub(crate) mod common;
8
9use proc_macro::TokenStream;
10use syn::{parse_macro_input, DeriveInput};
11
12/// Implement `Bundle` for a struct
13///
14/// Bundles can be passed directly to `World::spawn` and `World::insert`, and obtained from
15/// `World::remove`. Can be convenient when combined with other derives like `serde::Deserialize`.
16///
17/// # Example
18/// ```
19/// # use hecs::*;
20/// #[derive(Bundle)]
21/// struct Foo {
22///     x: i32,
23///     y: char,
24/// }
25///
26/// let mut world = World::new();
27/// let e = world.spawn(Foo { x: 42, y: 'a' });
28/// assert_eq!(*world.get::<&i32>(e).unwrap(), 42);
29/// ```
30#[proc_macro_derive(Bundle)]
31pub fn derive_bundle(input: TokenStream) -> TokenStream {
32    let input = parse_macro_input!(input as DeriveInput);
33    match bundle::derive(input) {
34        Ok(ts) => ts,
35        Err(e) => e.to_compile_error(),
36    }
37    .into()
38}
39
40/// Implement `DynamicBundleClone` for a struct.
41///
42/// This is an extension macro for bundles which allow them to be cloned, and
43/// subsequently used in `EntityBuilderClone::add_bundle`.
44///
45/// Requires that all fields of the struct implement [`Clone`].
46///
47/// The trait Bundle must also be implemented to be able to be used in
48/// entity builder.
49#[proc_macro_derive(DynamicBundleClone)]
50pub fn derive_dynamic_bundle_clone(input: TokenStream) -> TokenStream {
51    let input = parse_macro_input!(input as DeriveInput);
52    match bundle_clone::derive(input) {
53        Ok(ts) => ts,
54        Err(e) => e.to_compile_error(),
55    }
56    .into()
57}
58
59/// Implement `Query` for a struct or enum.
60///
61/// Queries can be passed to the type parameter of `World::query`. They must have exactly
62/// one lifetime parameter, and all of their fields must be queries (e.g. references) using that
63/// lifetime.
64///
65/// For enum queries, the result will always be the first variant that matches the entity.
66/// Unit variants and variants without any fields will always match an entity.
67///
68/// # Example
69/// ```
70/// # use hecs::*;
71/// #[derive(Query, Debug, PartialEq)]
72/// struct Foo<'a> {
73///     x: &'a i32,
74///     y: &'a mut bool,
75/// }
76///
77/// let mut world = World::new();
78/// let e = world.spawn((42, false));
79/// assert_eq!(
80///     world.query_one_mut::<Foo>(e).unwrap(),
81///     Foo {
82///         x: &42,
83///         y: &mut false
84///     }
85/// );
86/// ```
87#[proc_macro_derive(Query)]
88pub fn derive_query(input: TokenStream) -> TokenStream {
89    let input = parse_macro_input!(input as DeriveInput);
90    match query::derive(input) {
91        Ok(ts) => ts,
92        Err(e) => e.to_compile_error(),
93    }
94    .into()
95}
hecs_macros/lib.rs

hecs_macros/
lib.rs
