Auto merge of #17414 - jyc:space-separator, r=nox

style: Have OneOrMoreSeparated replace OneOrMoreCommaSeparated.

**NOTE** The alternative for me is just to duplicate the ToCss code, which is not bad and is less code changed! Don't know what others would think, though. Looking for feedback!

A future patch series has some values that should be separated by spaces. This
allows us to re-use the code for serialization, but the types do get a little
clunky. The separator is now indicated with an associated type.

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- [ ] These changes fix #__ (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [X] These changes do not require tests because they shoudl be tested by existing serialization code

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components/style/counter_style/mod.rs

@@ -19,7 +19,7 @@ use std::ascii::AsciiExt;
 use std::borrow::Cow;
 use std::fmt;
 use std::ops::Range;
-use style_traits::{ToCss, OneOrMoreCommaSeparated, ParseError, StyleParseError};
+use style_traits::{ToCss, OneOrMoreSeparated, CommaSeparator, ParseError, StyleParseError};
 use values::CustomIdent;
 
 /// Parse the prelude of an @counter-style rule
@@ -552,7 +552,9 @@ pub struct AdditiveTuple {
     pub symbol: Symbol,
 }
 
-impl OneOrMoreCommaSeparated for AdditiveTuple {}
+impl OneOrMoreSeparated for AdditiveTuple {
+    type S = CommaSeparator;
+}
 
 impl Parse for AdditiveTuple {
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {

components/style/font_face.rs

@@ -20,7 +20,7 @@ use parser::{ParserContext, log_css_error, Parse};
 use selectors::parser::SelectorParseError;
 use shared_lock::{SharedRwLockReadGuard, ToCssWithGuard};
 use std::fmt;
-use style_traits::{ToCss, OneOrMoreCommaSeparated, ParseError, StyleParseError};
+use style_traits::{ToCss, OneOrMoreSeparated, CommaSeparator, ParseError, StyleParseError};
 use values::specified::url::SpecifiedUrl;
 
 /// A source for a font-face rule.
@@ -34,7 +34,9 @@ pub enum Source {
     Local(FamilyName),
 }
 
-impl OneOrMoreCommaSeparated for Source {}
+impl OneOrMoreSeparated for Source {
+    type S = CommaSeparator;
+}
 
 /// A `UrlSource` represents a font-face source that has been specified with a
 /// `url()` function.

components/style/parser.rs

@@ -7,7 +7,7 @@
 use context::QuirksMode;
 use cssparser::{Parser, SourcePosition, UnicodeRange};
 use error_reporting::{ParseErrorReporter, ContextualParseError};
-use style_traits::{OneOrMoreCommaSeparated, ParseError, ParsingMode};
+use style_traits::{OneOrMoreSeparated, IsCommaSeparator, ParseError, ParsingMode};
 #[cfg(feature = "gecko")]
 use style_traits::{PARSING_MODE_DEFAULT, PARSING_MODE_ALLOW_UNITLESS_LENGTH, PARSING_MODE_ALLOW_ALL_NUMERIC_VALUES};
 use stylesheets::{CssRuleType, Origin, UrlExtraData, Namespaces};
@@ -161,7 +161,9 @@ pub trait Parse : Sized {
                      -> Result<Self, ParseError<'i>>;
 }
 
-impl<T> Parse for Vec<T> where T: Parse + OneOrMoreCommaSeparated {
+impl<T> Parse for Vec<T> where T: Parse + OneOrMoreSeparated,
+                               <T as OneOrMoreSeparated>::S: IsCommaSeparator
+{
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>)
                      -> Result<Self, ParseError<'i>> {
         input.parse_comma_separated(|input| T::parse(context, input))

components/style/values/generics/mod.rs

@@ -9,7 +9,7 @@ use counter_style::{Symbols, parse_counter_style_name};
 use cssparser::Parser;
 use parser::{Parse, ParserContext};
 use std::fmt;
-use style_traits::{OneOrMoreCommaSeparated, ToCss, ParseError, StyleParseError};
+use style_traits::{OneOrMoreSeparated, CommaSeparator, ToCss, ParseError, StyleParseError};
 use super::CustomIdent;
 use values::specified::url::SpecifiedUrl;
 
@@ -123,7 +123,9 @@ pub struct FontSettingTag<T> {
     pub value: T,
 }
 
-impl<T> OneOrMoreCommaSeparated for FontSettingTag<T> {}
+impl<T> OneOrMoreSeparated for FontSettingTag<T> {
+    type S = CommaSeparator;
+}
 
 impl<T: ToCss> ToCss for FontSettingTag<T> {
     fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {