Auto merge of #14274 - stshine:servo-url-index, r=emilio

Implement range index with the Position enum on ServoUrl

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [ ] 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 refactoring

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r? @emilio

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6 files changed, 35 insertions, 6 deletions

diff --git a/components/net/data_loader.rs b/components/net/data_loader.rs
index 19a6c92f0e2..7c26efac2a9 100644
--- a/components/net/data_loader.rs
+++ b/components/net/data_loader.rs
@@ -35,7 +35,7 @@ pub type DecodeData = (Mime, Vec<u8>);
 pub fn decode(url: &ServoUrl) -> Result<DecodeData, DecodeError> {
     assert_eq!(url.scheme(), "data");
     // Split out content type and data.
-    let parts: Vec<&str> = url.as_url().unwrap()[Position::BeforePath..Position::AfterQuery].splitn(2, ',').collect();
+    let parts: Vec<&str> = url[Position::BeforePath..Position::AfterQuery].splitn(2, ',').collect();
     if parts.len() != 2 {
         return Err(DecodeError::InvalidDataUri);
     }
diff --git a/components/net/http_loader.rs b/components/net/http_loader.rs
index 88826f9ed15..f40934d5e7c 100644
--- a/components/net/http_loader.rs
+++ b/components/net/http_loader.rs
@@ -931,7 +931,7 @@ pub fn load<A, B>(load_data: &LoadData,
     // the source rather than rendering the contents of the URL.
     let viewing_source = doc_url.scheme() == "view-source";
     if viewing_source {
-        doc_url = ServoUrl::parse(&load_data.url.as_url().unwrap()[Position::BeforeUsername..]).unwrap();
+        doc_url = ServoUrl::parse(&load_data.url[Position::BeforeUsername..]).unwrap();
     }
 
     // Loop to handle redirects.
diff --git a/components/script/dom/response.rs b/components/script/dom/response.rs
index 484a1d0beee..949bfdb0d47 100644
--- a/components/script/dom/response.rs
+++ b/components/script/dom/response.rs
@@ -358,7 +358,7 @@ impl ResponseMethods for Response {
 }
 
 fn serialize_without_fragment(url: &ServoUrl) -> &str {
-    &url.as_url().unwrap()[..Position::AfterQuery]
+    &url[..Position::AfterQuery]
 }
 
 impl Response {
diff --git a/components/script/dom/xmlhttprequest.rs b/components/script/dom/xmlhttprequest.rs
index 493e99cc957..a89c5c51799 100644
--- a/components/script/dom/xmlhttprequest.rs
+++ b/components/script/dom/xmlhttprequest.rs
@@ -878,7 +878,7 @@ impl XMLHttpRequest {
             },
         };
 
-        *self.response_url.borrow_mut() = metadata.final_url.as_url().unwrap()[..Position::AfterQuery].to_owned();
+        *self.response_url.borrow_mut() = metadata.final_url[..Position::AfterQuery].to_owned();
 
         // XXXManishearth Clear cache entries in case of a network error
         self.process_partial_response(XHRProgress::HeadersReceived(
diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index 30462f3823b..9b00846dbb3 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -1739,7 +1739,7 @@ impl ScriptThread {
             // Start with the scheme data of the parsed URL;
             // append question mark and query component, if any;
             // append number sign and fragment component if any.
-            let encoded = &incomplete.url.as_url().unwrap()[Position::BeforePath..];
+            let encoded = &incomplete.url[Position::BeforePath..];
 
             // Percent-decode (8.) and UTF-8 decode (9.)
             let script_source = percent_decode(encoded.as_bytes()).decode_utf8_lossy();
diff --git a/components/url/lib.rs b/components/url/lib.rs
index c0a02fff9f6..415b2dd4ea6 100644
--- a/components/url/lib.rs
+++ b/components/url/lib.rs
@@ -19,9 +19,10 @@ extern crate url;
 
 use std::fmt;
 use std::net::IpAddr;
+use std::ops::{Range, RangeFrom, RangeTo, RangeFull, Index};
 use std::path::Path;
 use std::sync::Arc;
-use url::{Url, Origin};
+use url::{Url, Origin, Position};
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf, Serialize, Deserialize))]
@@ -152,3 +153,31 @@ impl fmt::Display for ServoUrl {
         self.0.fmt(formatter)
     }
 }
+
+impl Index<RangeFull> for ServoUrl {
+    type Output = str;
+    fn index(&self, _: RangeFull) -> &str {
+        &self.0[..]
+    }
+}
+
+impl Index<RangeFrom<Position>> for ServoUrl {
+    type Output = str;
+    fn index(&self, range: RangeFrom<Position>) -> &str {
+        &self.0[range]
+    }
+}
+
+impl Index<RangeTo<Position>> for ServoUrl {
+    type Output = str;
+    fn index(&self, range: RangeTo<Position>) -> &str {
+        &self.0[range]
+    }
+}
+
+impl Index<Range<Position>> for ServoUrl {
+    type Output = str;
+    fn index(&self, range: Range<Position>) -> &str {
+        &self.0[range]
+    }
+}