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Introduce style_derive::cg

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This commit is contained in:
Anthony Ramine 2017-08-23 10:59:26 +02:00
parent 1c9c0334ba
commit f275895028
9 changed files with 289 additions and 483 deletions
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69
components/style_derive/to_animated_zero.rs
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@ -2,78 +2,31 @@
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
use cg;
use quote;
use syn;
use synstructure;
use synstructure::BindStyle;
pub fn derive(input: syn::DeriveInput) -> quote::Tokens {
let name = &input.ident;
let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
let mut where_clause = where_clause.clone();
for param in &input.generics.ty_params {
where_clause.predicates.push(
where_predicate(syn::Ty::Path(None, param.ident.clone().into())),
);
}
let (impl_generics, ty_generics, where_clause) = cg::trait_parts(
&input,
&["values", "animated", "ToAnimatedZero"],
);
let to_body = match_body(&input);
let to_body = cg::fmap_match(&input, BindStyle::Ref, |field| {
quote! { ::values::animated::ToAnimatedZero::to_animated_zero(#field)? }
});
quote! {
impl #impl_generics ::values::animated::ToAnimatedZero for #name #ty_generics #where_clause {
#[allow(unused_variables)]
#[inline]
fn to_animated_zero(&self) -> Result<Self, ()> {
match *self {
Ok(match *self {
#to_body
}
})
}
}
}
}
fn match_body(input: &syn::DeriveInput) -> quote::Tokens {
synstructure::each_variant(&input, &synstructure::BindStyle::Ref.into(), |fields, variant| {
let name = if let syn::Body::Enum(_) = input.body {
format!("{}::{}", input.ident, variant.ident).into()
} else {
variant.ident.clone()
};
let (zero, computed_fields) = synstructure::match_pattern(
&name,
&variant.data,
&synstructure::BindStyle::Move.into(),
);
let fields_pairs = fields.iter().zip(computed_fields.iter());
let mut computations = quote!();
computations.append_all(fields_pairs.map(|(field, computed_field)| {
quote! {
let #computed_field = ::values::animated::ToAnimatedZero::to_animated_zero(#field)?;
}
}));
Some(quote!(
#computations
Ok(#zero)
))
})
}
fn where_predicate(ty: syn::Ty) -> syn::WherePredicate {
syn::WherePredicate::BoundPredicate(syn::WhereBoundPredicate {
bound_lifetimes: vec![],
bounded_ty: ty,
bounds: vec![syn::TyParamBound::Trait(
syn::PolyTraitRef {
bound_lifetimes: vec![],
trait_ref: syn::Path {
global: true,
segments: vec![
"values".into(),
"animated".into(),
"ToAnimatedZero".into(),
],
},
},
syn::TraitBoundModifier::None,
)],
})
}