1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
/* This Source Code Form is subject to the terms of the Mozilla Public
* 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 animate::{AnimationVariantAttrs, AnimationFieldAttrs};
use cg;
use quote;
use syn;
use synstructure;
pub fn derive(input: syn::DeriveInput) -> quote::Tokens {
let name = &input.ident;
let trait_path = parse_quote!(values::animated::ToAnimatedZero);
let (impl_generics, ty_generics, mut where_clause) =
cg::trait_parts(&input, &trait_path);
let s = synstructure::Structure::new(&input);
let to_body = s.each_variant(|variant| {
let attrs = cg::parse_variant_attrs::<AnimationVariantAttrs>(&variant.ast());
if attrs.error {
return Some(quote! { Err(()) });
}
let (mapped, mapped_bindings) = cg::value(variant, "mapped");
let bindings_pairs = variant.bindings().into_iter().zip(mapped_bindings);
let mut computations = quote!();
computations.append_all(bindings_pairs.map(|(binding, mapped_binding)| {
let field_attrs = cg::parse_field_attrs::<AnimationFieldAttrs>(&binding.ast());
if field_attrs.constant {
if cg::is_parameterized(&binding.ast().ty, &where_clause.params, None) {
cg::add_predicate(
&mut where_clause.inner,
cg::where_predicate(
binding.ast().ty.clone(),
&parse_quote!(std::clone::Clone),
None,
),
);
}
quote! {
let #mapped_binding = ::std::clone::Clone::clone(#binding);
}
} else {
where_clause.add_trait_bound(&binding.ast().ty);
quote! {
let #mapped_binding =
::values::animated::ToAnimatedZero::to_animated_zero(#binding)?;
}
}
}));
computations.append_all(quote! { Ok(#mapped) });
Some(computations)
});
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 {
#to_body
}
}
}
}
}
|
