diff options
| -rw-r--r-- | ecs-macros/src/lib.rs | 67 |
1 files changed, 65 insertions, 2 deletions
diff --git a/ecs-macros/src/lib.rs b/ecs-macros/src/lib.rs index 8bfce38..8bef0b6 100644 --- a/ecs-macros/src/lib.rs +++ b/ecs-macros/src/lib.rs @@ -14,6 +14,7 @@ use syn::{ ItemStruct, ItemUnion, Path, + Type, }; use toml::value::{Table as TomlTable, Value as TomlValue}; @@ -46,6 +47,10 @@ pub fn component_derive(input: TokenStream) -> TokenStream { let item: TypeItem = parse::<Item>(input).unwrap().try_into().unwrap(); + let ComponentAttribute { ref_type, ref_mut_type } = item + .attribute::<ComponentAttribute>("component") + .unwrap_or_default(); + let item_ident = item.ident(); let (impl_generics, type_generics, where_clause) = item.generics().split_for_impl(); @@ -120,8 +125,8 @@ pub fn component_derive(input: TokenStream) -> TokenStream { type Component = Self; - type RefMut<'component> = ComponentRefMut<'component, Self>; - type Ref<'component> = ComponentRef<'component, Self>; + type RefMut<'component> = #ref_mut_type; + type Ref<'component> = #ref_type; fn id() -> Uid { @@ -369,3 +374,61 @@ fn find_engine_ecs_crate_path() -> Option<Path> None }) } + +#[derive(Debug)] +struct ComponentAttribute +{ + ref_type: proc_macro2::TokenStream, + ref_mut_type: proc_macro2::TokenStream, +} + +impl FromAttribute for ComponentAttribute +{ + fn from_attribute(attribute: &Attribute) -> Result<Self, syn::Error> + { + let mut ref_type: Option<Type> = None; + let mut ref_mut_type: Option<Type> = None; + + attribute.parse_nested_meta(|meta| { + let Some(flag) = meta.path.get_ident() else { + return Err(meta.error("Not a single identifier")); + }; + + if flag == "ref_type" { + let value = meta.value()?; + + ref_type = Some(value.parse::<Type>()?); + + return Ok(()); + } else if flag == "ref_mut_type" { + let value = meta.value()?; + + ref_mut_type = Some(value.parse::<Type>()?); + + return Ok(()); + } + + Err(meta.error("Unrecognized token")) + })?; + + Ok(Self { + ref_type: ref_type + .map(|ref_type| ref_type.into_token_stream()) + .unwrap_or_else(|| Self::default().ref_type), + ref_mut_type: ref_mut_type + .map(|ref_mut_type| ref_mut_type.into_token_stream()) + .unwrap_or_else(|| Self::default().ref_mut_type), + }) + } +} + +impl Default for ComponentAttribute +{ + fn default() -> Self + { + Self { + ref_type: quote! { ComponentRef<'component, Self> }, + ref_mut_type: quote! { ComponentRefMut<'component, Self> }, + } + } +} |