Make AsciiSet consts and fields values

Refs take 8 bytes, whereas the values are only 16 bytes, so there is not
a huge benefit to using references rather than values. PercentEncoding
is changed to store the AsciiSet as a value, and the functions that
previously accepted a reference now accept a value. This is a breaking
change for users who were passing a reference to AsciiSet to the
functions in the public API.

The AsciiSet consts (CONTROLS, NON_ALPHANUMERIC, etc.) are also changed
to be values.

This is an alternative to the non-breaking change in
<servo#976>

Discussion about the rationale for this is change is at
<servo#970 (comment)>

Author: joshka

percent_encoding/src/ascii_set.rs

@@ -22,9 +22,9 @@ use core::{mem, ops};
 /// use percent_encoding::{AsciiSet, CONTROLS};
 ///
 /// /// https://url.spec.whatwg.org/#fragment-percent-encode-set
-/// const FRAGMENT: &AsciiSet = &CONTROLS.add(b' ').add(b'"').add(b'<').add(b'>').add(b'`');
+/// const FRAGMENT: AsciiSet = CONTROLS.add(b' ').add(b'"').add(b'<').add(b'>').add(b'`');
 /// ```
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct AsciiSet {
     mask: [Chunk; ASCII_RANGE_LEN / BITS_PER_CHUNK],
 }
@@ -104,7 +104,7 @@ impl ops::Not for AsciiSet {
 /// Note that this includes the newline and tab characters, but not the space 0x20.
 ///
 /// <https://url.spec.whatwg.org/#c0-control-percent-encode-set>
-pub const CONTROLS: &AsciiSet = &AsciiSet {
+pub const CONTROLS: AsciiSet = AsciiSet {
     mask: [
         !0_u32, // C0: 0x00 to 0x1F (32 bits set)
         0,
@@ -134,7 +134,7 @@ static_assert! {
 /// Everything that is not an ASCII letter or digit.
 ///
 /// This is probably more eager than necessary in any context.
-pub const NON_ALPHANUMERIC: &AsciiSet = &CONTROLS
+pub const NON_ALPHANUMERIC: AsciiSet = CONTROLS
     .add(b' ')
     .add(b'!')
     .add(b'"')

percent_encoding/src/lib.rs

@@ -32,7 +32,7 @@
 //! use percent_encoding::{utf8_percent_encode, AsciiSet, CONTROLS};
 //!
 //! /// https://url.spec.whatwg.org/#fragment-percent-encode-set
-//! const FRAGMENT: &AsciiSet = &CONTROLS.add(b' ').add(b'"').add(b'<').add(b'>').add(b'`');
+//! const FRAGMENT: AsciiSet = CONTROLS.add(b' ').add(b'"').add(b'<').add(b'>').add(b'`');
 //!
 //! assert_eq!(utf8_percent_encode("foo <bar>", FRAGMENT).to_string(), "foo%20%3Cbar%3E");
 //! ```
@@ -114,7 +114,7 @@ pub fn percent_encode_byte(byte: u8) -> &'static str {
 /// assert_eq!(percent_encode(b"foo bar?", NON_ALPHANUMERIC).to_string(), "foo%20bar%3F");
 /// ```
 #[inline]
-pub fn percent_encode<'a>(input: &'a [u8], ascii_set: &'static AsciiSet) -> PercentEncode<'a> {
+pub fn percent_encode(input: &[u8], ascii_set: AsciiSet) -> PercentEncode<'_> {
     PercentEncode {
         bytes: input,
         ascii_set,
@@ -133,15 +133,15 @@ pub fn percent_encode<'a>(input: &'a [u8], ascii_set: &'static AsciiSet) -> Perc
 /// assert_eq!(utf8_percent_encode("foo bar?", NON_ALPHANUMERIC).to_string(), "foo%20bar%3F");
 /// ```
 #[inline]
-pub fn utf8_percent_encode<'a>(input: &'a str, ascii_set: &'static AsciiSet) -> PercentEncode<'a> {
+pub fn utf8_percent_encode(input: &str, ascii_set: AsciiSet) -> PercentEncode<'_> {
     percent_encode(input.as_bytes(), ascii_set)
 }
 
 /// The return type of [`percent_encode`] and [`utf8_percent_encode`].
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct PercentEncode<'a> {
     bytes: &'a [u8],
-    ascii_set: &'static AsciiSet,
+    ascii_set: AsciiSet,
 }
 
 impl<'a> Iterator for PercentEncode<'a> {
@@ -378,8 +378,8 @@ mod tests {
     }
 
     #[test]
-    fn percent_encode_accepts_ascii_set_ref() {
-        let encoded = percent_encode(b"foo bar?", &AsciiSet::EMPTY);
+    fn percent_encode_accepts_value() {
+        let encoded = percent_encode(b"foo bar?", AsciiSet::EMPTY);
         assert_eq!(encoded.collect::<String>(), "foo bar?");
     }
 
@@ -405,8 +405,8 @@ mod tests {
     }
 
     #[test]
-    fn utf8_percent_encode_accepts_ascii_set_ref() {
-        let encoded = super::utf8_percent_encode("foo bar?", &AsciiSet::EMPTY);
+    fn utf8_percent_encode_accepts_value() {
+        let encoded = super::utf8_percent_encode("foo bar?", AsciiSet::EMPTY);
         assert_eq!(encoded.collect::<String>(), "foo bar?");
     }
 

url/src/parser.rs

@@ -16,13 +16,13 @@ use form_urlencoded::EncodingOverride;
 use percent_encoding::{percent_encode, utf8_percent_encode, AsciiSet, CONTROLS};
 
 /// https://url.spec.whatwg.org/#fragment-percent-encode-set
-const FRAGMENT: &AsciiSet = &CONTROLS.add(b' ').add(b'"').add(b'<').add(b'>').add(b'`');
+const FRAGMENT: AsciiSet = CONTROLS.add(b' ').add(b'"').add(b'<').add(b'>').add(b'`');
 
 /// https://url.spec.whatwg.org/#path-percent-encode-set
-const PATH: &AsciiSet = &FRAGMENT.add(b'#').add(b'?').add(b'{').add(b'}');
+const PATH: AsciiSet = FRAGMENT.add(b'#').add(b'?').add(b'{').add(b'}');
 
 /// https://url.spec.whatwg.org/#userinfo-percent-encode-set
-pub(crate) const USERINFO: &AsciiSet = &PATH
+pub(crate) const USERINFO: AsciiSet = PATH
     .add(b'/')
     .add(b':')
     .add(b';')
@@ -34,15 +34,15 @@ pub(crate) const USERINFO: &AsciiSet = &PATH
     .add(b'^')
     .add(b'|');
 
-pub(crate) const PATH_SEGMENT: &AsciiSet = &PATH.add(b'/').add(b'%');
+pub(crate) const PATH_SEGMENT: AsciiSet = PATH.add(b'/').add(b'%');
 
 // The backslash (\) character is treated as a path separator in special URLs
 // so it needs to be additionally escaped in that case.
-pub(crate) const SPECIAL_PATH_SEGMENT: &AsciiSet = &PATH_SEGMENT.add(b'\\');
+pub(crate) const SPECIAL_PATH_SEGMENT: AsciiSet = PATH_SEGMENT.add(b'\\');
 
 // https://url.spec.whatwg.org/#query-state
-const QUERY: &AsciiSet = &CONTROLS.add(b' ').add(b'"').add(b'#').add(b'<').add(b'>');
-const SPECIAL_QUERY: &AsciiSet = &QUERY.add(b'\'');
+const QUERY: AsciiSet = CONTROLS.add(b' ').add(b'"').add(b'#').add(b'<').add(b'>');
+const SPECIAL_QUERY: AsciiSet = QUERY.add(b'\'');
 
 pub type ParseResult<T> = Result<T, ParseError>;