Auto merge of #17439 - bholley:compound_left_to_right, r=SimonSapin

Match compound selectors left-to-right (second try)

https://bugzilla.mozilla.org/show_bug.cgi?id=1373800

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components/style/dom.rs

@@ -21,8 +21,8 @@ use rule_tree::CascadeLevel;
 use selector_parser::{AttrValue, ElementExt, PreExistingComputedValues};
 use selector_parser::{PseudoClassStringArg, PseudoElement};
 use selectors::matching::{ElementSelectorFlags, VisitedHandlingMode};
+use selectors::sink::Push;
 use shared_lock::Locked;
-use sink::Push;
 use smallvec::VecLike;
 use std::fmt;
 #[cfg(feature = "gecko")] use std::collections::HashMap;

components/style/gecko/selector_parser.rs

@@ -310,7 +310,7 @@ impl<'a, 'i> ::selectors::Parser<'i> for SelectorParser<'a> {
                             Selector::parse(self, input)
                         })?;
                         // Selectors inside `:-moz-any` may not include combinators.
-                        if selectors.iter().flat_map(|x| x.iter_raw()).any(|s| s.is_combinator()) {
+                        if selectors.iter().flat_map(|x| x.iter_raw_match_order()).any(|s| s.is_combinator()) {
                             return Err(SelectorParseError::UnexpectedIdent("-moz-any".into()).into())
                         }
                         NonTSPseudoClass::MozAny(selectors.into_boxed_slice())

components/style/gecko/wrapper.rs

@@ -76,8 +76,8 @@ use selectors::Element;
 use selectors::attr::{AttrSelectorOperation, AttrSelectorOperator, CaseSensitivity, NamespaceConstraint};
 use selectors::matching::{ElementSelectorFlags, LocalMatchingContext, MatchingContext};
 use selectors::matching::{RelevantLinkStatus, VisitedHandlingMode};
+use selectors::sink::Push;
 use shared_lock::Locked;
-use sink::Push;
 use smallvec::VecLike;
 use std::cell::RefCell;
 use std::collections::HashMap;

components/style/invalidation/element/invalidator.rs

@@ -53,7 +53,7 @@ impl fmt::Debug for Invalidation {
         use cssparser::ToCss;
 
         f.write_str("Invalidation(")?;
-        for component in self.selector.iter_raw_rev_from(self.offset - 1) {
+        for component in self.selector.iter_raw_parse_order_from(self.offset - 1) {
             if matches!(*component, Component::Combinator(..)) {
                 break;
             }
@@ -568,7 +568,7 @@ impl<'a, 'b: 'a, E> TreeStyleInvalidator<'a, 'b, E>
                 if matches!(next_combinator, Combinator::PseudoElement) {
                     let pseudo_selector =
                         invalidation.selector
-                            .iter_raw_rev_from(next_combinator_offset - 1)
+                            .iter_raw_parse_order_from(next_combinator_offset - 1)
                             .next()
                             .unwrap();
                     let pseudo = match *pseudo_selector {

components/style/lib.rs

@@ -126,7 +126,6 @@ pub mod sharing;
 pub mod stylist;
 #[cfg(feature = "servo")] #[allow(unsafe_code)] pub mod servo;
 pub mod sequential;
-pub mod sink;
 pub mod str;
 pub mod style_adjuster;
 pub mod stylesheet_set;

components/style/selector_map.rs

@@ -369,15 +369,12 @@ impl<T: SelectorMapEntry> SelectorMap<T> {
     }
 }
 
-/// Searches the selector from right to left, beginning to the left of the
-/// ::pseudo-element (if any), and ending at the first combinator.
+/// Searches a compound selector from left to right. If the compound selector
+/// is a pseudo-element, it's ignored.
 ///
 /// The first non-None value returned from |f| is returned.
-///
-/// Effectively, pseudo-elements are ignored, given only state pseudo-classes
-/// may appear before them.
 #[inline(always)]
-fn find_from_right<F, R>(mut iter: SelectorIter<SelectorImpl>,
+fn find_from_left<F, R>(mut iter: SelectorIter<SelectorImpl>,
                          mut f: F)
                          -> Option<R>
     where F: FnMut(&Component<SelectorImpl>) -> Option<R>,
@@ -388,6 +385,8 @@ fn find_from_right<F, R>(mut iter: SelectorIter<SelectorImpl>,
         }
     }
 
+    // Effectively, pseudo-elements are ignored, given only state pseudo-classes
+    // may appear before them.
     if iter.next_sequence() == Some(Combinator::PseudoElement) {
         for ss in &mut iter {
             if let Some(r) = f(ss) {
@@ -403,7 +402,7 @@ fn find_from_right<F, R>(mut iter: SelectorIter<SelectorImpl>,
 #[inline(always)]
 pub fn get_id_name(iter: SelectorIter<SelectorImpl>)
                    -> Option<Atom> {
-    find_from_right(iter, |ss| {
+    find_from_left(iter, |ss| {
         // TODO(pradeep): Implement case-sensitivity based on the
         // document type and quirks mode.
         if let Component::ID(ref id) = *ss {
@@ -417,7 +416,7 @@ pub fn get_id_name(iter: SelectorIter<SelectorImpl>)
 #[inline(always)]
 pub fn get_class_name(iter: SelectorIter<SelectorImpl>)
                       -> Option<Atom> {
-    find_from_right(iter, |ss| {
+    find_from_left(iter, |ss| {
         // TODO(pradeep): Implement case-sensitivity based on the
         // document type and quirks mode.
         if let Component::Class(ref class) = *ss {
@@ -431,7 +430,7 @@ pub fn get_class_name(iter: SelectorIter<SelectorImpl>)
 #[inline(always)]
 pub fn get_local_name(iter: SelectorIter<SelectorImpl>)
                       -> Option<LocalNameSelector<SelectorImpl>> {
-    find_from_right(iter, |ss| {
+    find_from_left(iter, |ss| {
         if let Component::LocalName(ref n) = *ss {
             return Some(LocalNameSelector {
                 name: n.name.clone(),

components/style/sink.rs

@@ -1,53 +0,0 @@
-/* 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/. */
-
-//! Small helpers to abstract over different containers.
-#![deny(missing_docs)]
-
-use smallvec::{Array, SmallVec};
-use std::marker::PhantomData;
-
-/// A trait to abstract over a `push` method that may be implemented for
-/// different kind of types.
-///
-/// Used to abstract over `Array`, `SmallVec` and `Vec`, and also to implement a
-/// type which `push` method does only tweak a byte when we only need to check
-/// for the presence of something.
-pub trait Push<T> {
-    /// Push a value into self.
-    fn push(&mut self, value: T);
-}
-
-impl<T> Push<T> for Vec<T> {
-    fn push(&mut self, value: T) {
-        Vec::push(self, value);
-    }
-}
-
-impl<A: Array> Push<A::Item> for SmallVec<A> {
-    fn push(&mut self, value: A::Item) {
-        SmallVec::push(self, value);
-    }
-}
-
-/// A struct that implements `Push`, but only stores whether it's empty.
-pub struct ForgetfulSink<T>(bool, PhantomData<T>);
-
-impl<T> ForgetfulSink<T> {
-    /// Trivially construct a new `ForgetfulSink`.
-    pub fn new() -> Self {
-        ForgetfulSink(true, PhantomData)
-    }
-
-    /// Whether this sink is empty or not.
-    pub fn is_empty(&self) -> bool {
-        self.0
-    }
-}
-
-impl<T> Push<T> for ForgetfulSink<T> {
-    fn push(&mut self, _value: T) {
-        self.0 = false;
-    }
-}

components/style/stylist.rs

@@ -31,9 +31,9 @@ use selectors::matching::{ElementSelectorFlags, matches_selector, MatchingContex
 use selectors::matching::AFFECTED_BY_PRESENTATIONAL_HINTS;
 use selectors::parser::{AncestorHashes, Combinator, Component, Selector, SelectorAndHashes};
 use selectors::parser::{SelectorIter, SelectorMethods};
+use selectors::sink::Push;
 use selectors::visitor::SelectorVisitor;
 use shared_lock::{Locked, SharedRwLockReadGuard, StylesheetGuards};
-use sink::Push;
 use smallvec::VecLike;
 use std::fmt::Debug;
 #[cfg(feature = "servo")]