Various minor/cosmetic improvements to code

[rust.git] / src / libcore / str / mod.rs

diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index a316093825ad75db5082612a33049346c27bcdd8..4a22d929fede0e3db0721dad190da09780b11c0a 100644 (file)
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -482,7 +482,7 @@ fn utf8_first_byte(byte: u8, width: u32) -> u32 { (byte & (0x7F >> width)) as u3
 #[inline]
 fn utf8_acc_cont_byte(ch: u32, byte: u8) -> u32 { (ch << 6) | (byte & CONT_MASK) as u32 }
 
-/// Checks whether the byte is a UTF-8 continuation byte (i.e. starts with the
+/// Checks whether the byte is a UTF-8 continuation byte (i.e., starts with the
 /// bits `10`).
 #[inline]
 fn utf8_is_cont_byte(byte: u8) -> bool { (byte & !CONT_MASK) == TAG_CONT_U8 }
@@ -536,10 +536,9 @@ fn next_code_point_reverse<'a, I>(bytes: &mut I) -> Option<u32>
     where I: DoubleEndedIterator<Item = &'a u8>,
 {
     // Decode UTF-8
-    let w = match bytes.next_back() {
-        None => return None,
-        Some(&next_byte) if next_byte < 128 => return Some(next_byte as u32),
-        Some(&back_byte) => back_byte,
+    let w = match *bytes.next_back()? {
+        next_byte if next_byte < 128 => return Some(next_byte as u32),
+        back_byte => back_byte,
     };
 
     // Multibyte case follows
@@ -1424,10 +1423,8 @@ fn contains_nonascii(x: usize) -> bool {
     (x & NONASCII_MASK) != 0
 }
 
-/// Walks through `iter` checking that it's a valid UTF-8 sequence,
-/// returning `true` in that case, or, if it is invalid, `false` with
-/// `iter` reset such that it is pointing at the first byte in the
-/// invalid sequence.
+/// Walks through `v` checking that it's a valid UTF-8 sequence,
+/// returning `Ok(())` in that case, or, if it is invalid, `Err(err)`.
 #[inline]
 fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> {
     let mut index = 0;