Implement #[css(derive_debug)]

This makes #[derive(ToCss)] derive Debug with a simple call to the to_css method.
This commit is contained in:
Anthony Ramine 2017-08-26 16:55:42 +02:00
parent 1ace6d4c7f
commit 4faadb489f
2 changed files with 33 additions and 41 deletions

View file

@ -3,21 +3,22 @@
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
use cg;
use quote;
use syn;
use quote::Tokens;
use syn::DeriveInput;
use synstructure;
pub fn derive(input: syn::DeriveInput) -> quote::Tokens {
pub fn derive(input: DeriveInput) -> Tokens {
let name = &input.ident;
let trait_path = &["style_traits", "ToCss"];
let (impl_generics, ty_generics, mut where_clause) =
cg::trait_parts(&input, trait_path);
let input_attrs = cg::parse_input_attrs::<CssInputAttrs>(&input);
let style = synstructure::BindStyle::Ref.into();
let match_body = synstructure::each_variant(&input, &style, |bindings, variant| {
let mut identifier = to_css_identifier(variant.ident.as_ref());
let css_attrs = cg::parse_variant_attrs::<CssAttrs>(variant);
let separator = if css_attrs.comma { ", " } else { " " };
let variant_attrs = cg::parse_variant_attrs::<CssVariantAttrs>(variant);
let separator = if variant_attrs.comma { ", " } else { " " };
let mut expr = if !bindings.is_empty() {
let mut expr = quote! {};
for binding in bindings {
@ -37,7 +38,7 @@ pub fn derive(input: syn::DeriveInput) -> quote::Tokens {
::std::fmt::Write::write_str(dest, #identifier)
}
};
if css_attrs.function {
if variant_attrs.function {
identifier.push_str("(");
expr = quote! {
::std::fmt::Write::write_str(dest, #identifier)?;
@ -48,7 +49,7 @@ pub fn derive(input: syn::DeriveInput) -> quote::Tokens {
Some(expr)
});
quote! {
let mut impls = quote! {
impl #impl_generics ::style_traits::ToCss for #name #ty_generics #where_clause {
#[allow(unused_variables)]
#[inline]
@ -61,12 +62,32 @@ pub fn derive(input: syn::DeriveInput) -> quote::Tokens {
}
}
}
};
if input_attrs.derive_debug {
impls.append(quote! {
impl #impl_generics ::std::fmt::Debug for #name #ty_generics #where_clause {
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
::style_traits::ToCss::to_css(self, f)
}
}
});
}
impls
}
#[derive(Default, FromVariant)]
#[darling(attributes(css), default)]
struct CssAttrs {
#[derive(Default, FromDeriveInput)]
struct CssInputAttrs {
derive_debug: bool,
function: bool,
comma: bool,
}
#[darling(attributes(css), default)]
#[derive(Default, FromVariant)]
struct CssVariantAttrs {
function: bool,
comma: bool,
}