Thread ParseError return values through CSS parsing.

components/style/media_queries.rs

@@ -8,12 +8,13 @@
 
 use Atom;
 use context::QuirksMode;
-use cssparser::{Delimiter, Parser, Token};
+use cssparser::{Delimiter, Parser, Token, ParserInput};
 use parser::ParserContext;
+use selectors::parser::SelectorParseError;
 use serialize_comma_separated_list;
 use std::ascii::AsciiExt;
 use std::fmt;
-use style_traits::ToCss;
+use style_traits::{ToCss, ParseError, StyleParseError};
 
 #[cfg(feature = "servo")]
 pub use servo::media_queries::{Device, Expression};
@@ -209,7 +210,8 @@ impl MediaQuery {
     /// Parse a media query given css input.
     ///
     /// Returns an error if any of the expressions is unknown.
-    pub fn parse(context: &ParserContext, input: &mut Parser) -> Result<MediaQuery, ()> {
+    pub fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>)
+                         -> Result<MediaQuery, ParseError<'i>> {
         let mut expressions = vec![];
 
         let qualifier = if input.try(|input| input.expect_ident_matching("only")).is_ok() {
@@ -221,11 +223,15 @@ impl MediaQuery {
         };
 
         let media_type = match input.try(|input| input.expect_ident()) {
-            Ok(ident) => try!(MediaQueryType::parse(&*ident)),
-            Err(()) => {
+            Ok(ident) => {
+                let result: Result<_, ParseError> = MediaQueryType::parse(&*ident)
+                    .map_err(|()| SelectorParseError::UnexpectedIdent(ident).into());
+                try!(result)
+            }
+            Err(_) => {
                 // Media type is only optional if qualifier is not specified.
                 if qualifier.is_some() {
-                    return Err(())
+                    return Err(StyleParseError::UnspecifiedError.into())
                 }
 
                 // Without a media type, require at least one expression.
@@ -270,7 +276,7 @@ pub fn parse_media_query_list(context: &ParserContext, input: &mut Parser) -> Me
         match input.next() {
             Ok(Token::Comma) => {},
             Ok(_) => unreachable!(),
-            Err(()) => break,
+            Err(_) => break,
         }
     }
 
@@ -311,7 +317,8 @@ impl MediaList {
     ///
     /// Returns true if added, false if fail to parse the medium string.
     pub fn append_medium(&mut self, context: &ParserContext, new_medium: &str) -> bool {
-        let mut parser = Parser::new(new_medium);
+        let mut input = ParserInput::new(new_medium);
+        let mut parser = Parser::new(&mut input);
         let new_query = match MediaQuery::parse(&context, &mut parser) {
             Ok(query) => query,
             Err(_) => { return false; }
@@ -329,7 +336,8 @@ impl MediaList {
     ///
     /// Returns true if found and deleted, false otherwise.
     pub fn delete_medium(&mut self, context: &ParserContext, old_medium: &str) -> bool {
-        let mut parser = Parser::new(old_medium);
+        let mut input = ParserInput::new(old_medium);
+        let mut parser = Parser::new(&mut input);
         let old_query = match MediaQuery::parse(context, &mut parser) {
             Ok(query) => query,
             Err(_) => { return false; }