gecko-dev/servo/components/style/macros.rs

122 строки
3.3 KiB
Rust

/* 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/. */
//! Various macro helpers.
macro_rules! exclusive_value {
(($value:ident, $set:expr) => $ident:path) => {
if $value.intersects($set) {
return Err(());
} else {
$ident
}
};
}
#[cfg(feature = "gecko")]
macro_rules! impl_gecko_keyword_conversions {
($name:ident, $utype:ty) => {
impl From<$utype> for $name {
fn from(bits: $utype) -> $name {
$name::from_gecko_keyword(bits)
}
}
impl From<$name> for $utype {
fn from(v: $name) -> $utype {
v.to_gecko_keyword()
}
}
};
}
macro_rules! trivial_to_computed_value {
($name:ty) => {
impl $crate::values::computed::ToComputedValue for $name {
type ComputedValue = $name;
fn to_computed_value(&self, _: &$crate::values::computed::Context) -> Self {
self.clone()
}
fn from_computed_value(other: &Self) -> Self {
other.clone()
}
}
};
}
/// A macro to parse an identifier, or return an `UnexpectedIdent` error
/// otherwise.
///
/// FIXME(emilio): The fact that `UnexpectedIdent` is a `SelectorParseError`
/// doesn't make a lot of sense to me.
macro_rules! try_match_ident_ignore_ascii_case {
($input:expr, $( $match_body:tt )*) => {{
let location = $input.current_source_location();
let ident = $input.expect_ident_cloned()?;
match_ignore_ascii_case! { &ident,
$( $match_body )*
_ => return Err(location.new_custom_error(
::selectors::parser::SelectorParseErrorKind::UnexpectedIdent(ident.clone())
))
}
}}
}
macro_rules! define_keyword_type {
($name:ident, $css:expr) => {
#[allow(missing_docs)]
#[derive(
Animate,
Clone,
ComputeSquaredDistance,
Copy,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToAnimatedValue,
ToAnimatedZero,
ToComputedValue,
ToCss,
)]
pub struct $name;
impl fmt::Debug for $name {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str($css)
}
}
impl $crate::parser::Parse for $name {
fn parse<'i, 't>(
_context: &$crate::parser::ParserContext,
input: &mut ::cssparser::Parser<'i, 't>,
) -> Result<$name, ::style_traits::ParseError<'i>> {
input
.expect_ident_matching($css)
.map(|_| $name)
.map_err(|e| e.into())
}
}
};
}
#[cfg(feature = "gecko")]
macro_rules! impl_bitflags_conversions {
($name:ident) => {
impl From<u8> for $name {
fn from(bits: u8) -> $name {
$name::from_bits(bits).expect("bits contain valid flag")
}
}
impl From<$name> for u8 {
fn from(v: $name) -> u8 {
v.bits()
}
}
};
}