From 72b29d3202f1808ec96291403fd28f2b72497d78 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Sun, 2 Sep 2018 22:54:12 +0000
Subject: [PATCH] style: Simplify the Lang pseudo-class stuff a bit.

Differential Revision: https://phabricator.services.mozilla.com/D4754
---
 components/style/dom.rs                       |  4 +-
 .../style/gecko/non_ts_pseudo_class_list.rs   | 16 +---
 components/style/gecko/selector_parser.rs     | 85 ++++++++-----------
 components/style/gecko/wrapper.rs             |  4 +-
 components/style/servo/selector_parser.rs     |  6 +-
 5 files changed, 45 insertions(+), 70 deletions(-)

diff --git a/components/style/dom.rs b/components/style/dom.rs
index 7552505a752..2f65a266f01 100644
--- a/components/style/dom.rs
+++ b/components/style/dom.rs
@@ -19,7 +19,7 @@ use element_state::ElementState;
 use font_metrics::FontMetricsProvider;
 use media_queries::Device;
 use properties::{AnimationRules, ComputedValues, PropertyDeclarationBlock};
-use selector_parser::{AttrValue, PseudoClassStringArg, PseudoElement, SelectorImpl};
+use selector_parser::{AttrValue, Lang, PseudoElement, SelectorImpl};
 use selectors::Element as SelectorsElement;
 use selectors::matching::{ElementSelectorFlags, QuirksMode, VisitedHandlingMode};
 use selectors::sink::Push;
@@ -895,7 +895,7 @@ pub trait TElement:
     fn match_element_lang(
         &self,
         override_lang: Option<Option<AttrValue>>,
-        value: &PseudoClassStringArg,
+        value: &Lang,
     ) -> bool;
 
     /// Returns whether this element is the main body element of the HTML
diff --git a/components/style/gecko/non_ts_pseudo_class_list.rs b/components/style/gecko/non_ts_pseudo_class_list.rs
index 04f57b73885..813250e4383 100644
--- a/components/style/gecko/non_ts_pseudo_class_list.rs
+++ b/components/style/gecko/non_ts_pseudo_class_list.rs
@@ -12,22 +12,13 @@
  * Expected usage is as follows:
  * ```
  * macro_rules! pseudo_class_macro{
- *     (bare: [$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*],
- *      string: [$(($s_css:expr, $s_name:ident, $s_gecko_type:tt, $s_state:tt, $s_flags:tt),)*]) => {
- *      keyword: [$(($k_css:expr, $k_name:ident, $k_gecko_type:tt, $k_state:tt, $k_flags:tt),)*]) => {
+ *     ([$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*]) => {
  *         // do stuff
  *     }
  * }
  * apply_non_ts_list!(pseudo_class_macro)
  * ```
  *
- * The `string` and `keyword` variables will be applied to pseudoclasses that are of the form of
- * functions with string or keyword arguments.
- *
- * Pending pseudo-classes:
- *
- *  :scope -> <style scoped>, pending discussion.
- *
  * $gecko_type can be either "_" or an ident in Gecko's CSSPseudoClassType.
  * $state can be either "_" or an expression of type ElementState.  If present,
  *        the semantics are that the pseudo-class matches if any of the bits in
@@ -39,7 +30,7 @@
 macro_rules! apply_non_ts_list {
     ($apply_macro:ident) => {
         $apply_macro! {
-            bare: [
+            [
                 ("-moz-table-border-nonzero", MozTableBorderNonzero, mozTableBorderNonzero, _, PSEUDO_CLASS_ENABLED_IN_UA_SHEETS),
                 ("-moz-browser-frame", MozBrowserFrame, mozBrowserFrame, _, PSEUDO_CLASS_ENABLED_IN_UA_SHEETS_AND_CHROME),
                 ("link", Link, link, IN_UNVISITED_STATE, _),
@@ -111,9 +102,6 @@ macro_rules! apply_non_ts_list {
                 ("-moz-lwtheme-brighttext", MozLWThemeBrightText, mozLWThemeBrightText, _, _),
                 ("-moz-lwtheme-darktext", MozLWThemeDarkText, mozLWThemeDarkText, _, _),
                 ("-moz-window-inactive", MozWindowInactive, mozWindowInactive, _, _),
-            ],
-            string: [
-                ("lang", Lang, lang, _, _),
             ]
         }
     }
diff --git a/components/style/gecko/selector_parser.rs b/components/style/gecko/selector_parser.rs
index 32a7b1f6ad0..3f6fee3c30e 100644
--- a/components/style/gecko/selector_parser.rs
+++ b/components/style/gecko/selector_parser.rs
@@ -37,12 +37,11 @@ bitflags! {
     }
 }
 
-/// The type used for storing pseudo-class string arguments.
-pub type PseudoClassStringArg = Atom;
+/// The type used to store the language argument to the `:lang` pseudo-class.
+pub type Lang = Atom;
 
 macro_rules! pseudo_class_name {
-    (bare: [$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*],
-     string: [$(($s_css:expr, $s_name:ident, $s_gecko_type:tt, $s_state:tt, $s_flags:tt),)*]) => {
+    ([$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*]) => {
         /// Our representation of a non tree-structural pseudo-class.
         #[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq)]
         pub enum NonTSPseudoClass {
@@ -50,10 +49,8 @@ macro_rules! pseudo_class_name {
                 #[doc = $css]
                 $name,
             )*
-            $(
-                #[doc = $s_css]
-                $s_name(PseudoClassStringArg),
-            )*
+            /// The `:lang` pseudo-class.
+            Lang(Lang),
             /// The `:dir` pseudo-class.
             Dir(Direction),
             /// The non-standard `:-moz-any` pseudo-class.
@@ -74,15 +71,14 @@ impl ToCss for NonTSPseudoClass {
         W: fmt::Write,
     {
         macro_rules! pseudo_class_serialize {
-            (bare: [$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*],
-             string: [$(($s_css:expr, $s_name:ident, $s_gecko_type:tt, $s_state:tt, $s_flags:tt),)*]) => {
+            ([$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*]) => {
                 match *self {
                     $(NonTSPseudoClass::$name => concat!(":", $css),)*
-                    $(NonTSPseudoClass::$s_name(ref s) => {
-                        write!(dest, concat!(":", $s_css, "("))?;
+                    NonTSPseudoClass::Lang(ref s) => {
+                        dest.write_str(":lang(")?;
                         serialize_atom_identifier(s, dest)?;
                         return dest.write_char(')');
-                    }, )*
+                    },
                     NonTSPseudoClass::MozLocaleDir(ref dir) => {
                         dest.write_str(":-moz-locale-dir(")?;
                         dir.to_css(&mut CssWriter::new(dest))?;
@@ -137,8 +133,7 @@ impl NonTSPseudoClass {
     /// in a particular state.
     pub fn parse_non_functional(name: &str) -> Option<Self> {
         macro_rules! pseudo_class_parse {
-            (bare: [$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*],
-             string: [$(($s_css:expr, $s_name:ident, $s_gecko_type:tt, $s_state:tt, $s_flags:tt),)*]) => {
+            ([$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*]) => {
                 match_ignore_ascii_case! { &name,
                     $($css => Some(NonTSPseudoClass::$name),)*
                     _ => None,
@@ -159,12 +154,11 @@ impl NonTSPseudoClass {
             };
         }
         macro_rules! pseudo_class_check_is_enabled_in {
-            (bare: [$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*],
-            string: [$(($s_css:expr, $s_name:ident, $s_gecko_type:tt, $s_state:tt, $s_flags:tt),)*]) => {
+            ([$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*]) => {
                 match *self {
                     $(NonTSPseudoClass::$name => check_flag!($flags),)*
-                    $(NonTSPseudoClass::$s_name(..) => check_flag!($s_flags),)*
                     NonTSPseudoClass::MozLocaleDir(_) |
+                    NonTSPseudoClass::Lang(_) |
                     NonTSPseudoClass::Dir(_) |
                     NonTSPseudoClass::MozAny(_) => false,
                 }
@@ -214,13 +208,12 @@ impl NonTSPseudoClass {
             };
         }
         macro_rules! pseudo_class_state {
-            (bare: [$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*],
-             string: [$(($s_css:expr, $s_name:ident, $s_gecko_type:tt, $s_state:tt, $s_flags:tt),)*]) => {
+            ([$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*]) => {
                 match *self {
                     $(NonTSPseudoClass::$name => flag!($state),)*
-                    $(NonTSPseudoClass::$s_name(..) => flag!($s_state),)*
                     NonTSPseudoClass::Dir(..) |
                     NonTSPseudoClass::MozLocaleDir(..) |
+                    NonTSPseudoClass::Lang(..) |
                     NonTSPseudoClass::MozAny(..) => ElementState::empty(),
                 }
             }
@@ -391,35 +384,29 @@ impl<'a, 'i> ::selectors::Parser<'i> for SelectorParser<'a> {
         name: CowRcStr<'i>,
         parser: &mut Parser<'i, 't>,
     ) -> Result<NonTSPseudoClass, ParseError<'i>> {
-        macro_rules! pseudo_class_string_parse {
-            (bare: [$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*],
-             string: [$(($s_css:expr, $s_name:ident, $s_gecko_type:tt, $s_state:tt, $s_flags:tt),)*]) => {
-                match_ignore_ascii_case! { &name,
-                    $($s_css => {
-                        let name = parser.expect_ident_or_string()?;
-                        NonTSPseudoClass::$s_name(Atom::from(name.as_ref()))
-                    }, )*
-                    "-moz-locale-dir" => {
-                        NonTSPseudoClass::MozLocaleDir(Direction::parse(parser)?)
-                    },
-                    "dir" => {
-                        NonTSPseudoClass::Dir(Direction::parse(parser)?)
-                    },
-                    "-moz-any" => {
-                        NonTSPseudoClass::MozAny(
-                            selector_parser::parse_compound_selector_list(
-                                self,
-                                parser,
-                            )?.into()
-                        )
-                    }
-                    _ => return Err(parser.new_custom_error(
-                        SelectorParseErrorKind::UnsupportedPseudoClassOrElement(name.clone())
-                    ))
-                }
+        let pseudo_class = match_ignore_ascii_case! { &name,
+            "lang" => {
+                let name = parser.expect_ident_or_string()?;
+                NonTSPseudoClass::Lang(Atom::from(name.as_ref()))
+            },
+            "-moz-locale-dir" => {
+                NonTSPseudoClass::MozLocaleDir(Direction::parse(parser)?)
+            },
+            "dir" => {
+                NonTSPseudoClass::Dir(Direction::parse(parser)?)
+            },
+            "-moz-any" => {
+                NonTSPseudoClass::MozAny(
+                    selector_parser::parse_compound_selector_list(
+                        self,
+                        parser,
+                    )?.into()
+                )
             }
-        }
-        let pseudo_class = apply_non_ts_list!(pseudo_class_string_parse);
+            _ => return Err(parser.new_custom_error(
+                SelectorParseErrorKind::UnsupportedPseudoClassOrElement(name.clone())
+            ))
+        };
         if self.is_pseudo_class_enabled(&pseudo_class) {
             Ok(pseudo_class)
         } else {
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index 031a9f40fdd..ff5ae599fcb 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -69,7 +69,7 @@ use properties::{Importance, PropertyDeclaration, PropertyDeclarationBlock};
 use properties::animated_properties::{AnimationValue, AnimationValueMap};
 use properties::style_structs::Font;
 use rule_tree::CascadeLevel as ServoCascadeLevel;
-use selector_parser::{AttrValue, HorizontalDirection, PseudoClassStringArg};
+use selector_parser::{AttrValue, HorizontalDirection, Lang};
 use selectors::{Element, OpaqueElement};
 use selectors::attr::{AttrSelectorOperation, AttrSelectorOperator};
 use selectors::attr::{CaseSensitivity, NamespaceConstraint};
@@ -1716,7 +1716,7 @@ impl<'le> TElement for GeckoElement<'le> {
     fn match_element_lang(
         &self,
         override_lang: Option<Option<AttrValue>>,
-        value: &PseudoClassStringArg,
+        value: &Lang,
     ) -> bool {
         // Gecko supports :lang() from CSS Selectors 3, which only accepts a
         // single language tag, and which performs simple dash-prefix matching
diff --git a/components/style/servo/selector_parser.rs b/components/style/servo/selector_parser.rs
index 2083539f51b..6b5efac54f2 100644
--- a/components/style/servo/selector_parser.rs
+++ b/components/style/servo/selector_parser.rs
@@ -284,8 +284,8 @@ impl PseudoElement {
     }
 }
 
-/// The type used for storing pseudo-class string arguments.
-pub type PseudoClassStringArg = Box<str>;
+/// The type used for storing `:lang` arguments.
+pub type Lang = Box<str>;
 
 /// A non tree-structural pseudo-class.
 /// See https://drafts.csswg.org/selectors-4/#structural-pseudos
@@ -302,7 +302,7 @@ pub enum NonTSPseudoClass {
     Fullscreen,
     Hover,
     Indeterminate,
-    Lang(PseudoClassStringArg),
+    Lang(Lang),
     Link,
     PlaceholderShown,
     ReadWrite,