diff --git a/color/tests.rs b/color/tests.rs
index babb076b..85eb430e 100644
--- a/color/tests.rs
+++ b/color/tests.rs
@@ -3,25 +3,21 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use super::*;
-use crate::{ColorParser, PredefinedColorSpace, Color, RgbaLegacy};
-use cssparser::{Parser, ParserInput};
-use serde_json::{self, json, Value};
+use cssparser::ParserInput;
+use serde_json::{json, Value};
 
 fn almost_equals(a: &Value, b: &Value) -> bool {
     match (a, b) {
-        (&Value::Number(ref a), &Value::Number(ref b)) => {
+        (Value::Number(a), Value::Number(b)) => {
             let a = a.as_f64().unwrap();
             let b = b.as_f64().unwrap();
             (a - b).abs() <= a.abs() * 1e-6
         }
 
         (&Value::Bool(a), &Value::Bool(b)) => a == b,
-        (&Value::String(ref a), &Value::String(ref b)) => a == b,
-        (&Value::Array(ref a), &Value::Array(ref b)) => {
-            a.len() == b.len()
-                && a.iter()
-                    .zip(b.iter())
-                    .all(|(ref a, ref b)| almost_equals(*a, *b))
+        (Value::String(a), Value::String(b)) => a == b,
+        (Value::Array(a), Value::Array(b)) => {
+            a.len() == b.len() && a.iter().zip(b.iter()).all(|(a, b)| almost_equals(a, b))
         }
         (&Value::Object(_), &Value::Object(_)) => panic!("Not implemented"),
         (&Value::Null, &Value::Null) => true,
@@ -43,8 +39,7 @@ fn assert_json_eq(results: Value, expected: Value, message: &str) {
     }
 }
 
-
-fn run_raw_json_tests<F: Fn(Value, Value) -> ()>(json_data: &str, run: F) {
+fn run_raw_json_tests<F: Fn(Value, Value)>(json_data: &str, run: F) {
     let items = match serde_json::from_str(json_data) {
         Ok(Value::Array(items)) => items,
         other => panic!("Invalid JSON: {:?}", other),
@@ -92,11 +87,14 @@ fn color3() {
 #[cfg_attr(all(miri, feature = "skip_long_tests"), ignore)]
 #[test]
 fn color3_hsl() {
-    run_color_tests(include_str!("../src/css-parsing-tests/color3_hsl.json"), |c| {
-        c.ok()
-            .map(|v| v.to_css_string().to_json())
-            .unwrap_or(Value::Null)
-    })
+    run_color_tests(
+        include_str!("../src/css-parsing-tests/color3_hsl.json"),
+        |c| {
+            c.ok()
+                .map(|v| v.to_css_string().to_json())
+                .unwrap_or(Value::Null)
+        },
+    )
 }
 
 /// color3_keywords.json is different: R, G and B are in 0..255 rather than 0..1
@@ -115,11 +113,14 @@ fn color3_keywords() {
 #[cfg_attr(all(miri, feature = "skip_long_tests"), ignore)]
 #[test]
 fn color4_hwb() {
-    run_color_tests(include_str!("../src/css-parsing-tests/color4_hwb.json"), |c| {
-        c.ok()
-            .map(|v| v.to_css_string().to_json())
-            .unwrap_or(Value::Null)
-    })
+    run_color_tests(
+        include_str!("../src/css-parsing-tests/color4_hwb.json"),
+        |c| {
+            c.ok()
+                .map(|v| v.to_css_string().to_json())
+                .unwrap_or(Value::Null)
+        },
+    )
 }
 
 #[cfg_attr(all(miri, feature = "skip_long_tests"), ignore)]
@@ -355,7 +356,7 @@ fn generic_parser() {
     ];
 
     for (input, expected) in TESTS {
-        let mut input = ParserInput::new(*input);
+        let mut input = ParserInput::new(input);
         let mut input = Parser::new(&mut input);
 
         let actual: OutputType = parse_color_with(&TestColorParser, &mut input).unwrap();
diff --git a/macros/lib.rs b/macros/lib.rs
index 4354cc8e..8b40bd4c 100644
--- a/macros/lib.rs
+++ b/macros/lib.rs
@@ -48,9 +48,7 @@ fn get_byte_from_lit(lit: &syn::Lit) -> u8 {
 
 fn get_byte_from_expr_lit(expr: &syn::Expr) -> u8 {
     match *expr {
-        syn::Expr::Lit(syn::ExprLit { ref lit, .. }) => {
-            get_byte_from_lit(lit)
-        }
+        syn::Expr::Lit(syn::ExprLit { ref lit, .. }) => get_byte_from_lit(lit),
         _ => unreachable!(),
     }
 }
@@ -63,15 +61,17 @@ fn parse_pat_to_table<'a>(
     table: &mut [u8; 256],
 ) {
     match pat {
-        &syn::Pat::Lit(syn::PatLit { ref lit, .. }) => {
+        syn::Pat::Lit(syn::PatLit { ref lit, .. }) => {
             let value = get_byte_from_lit(lit);
             if table[value as usize] == 0 {
                 table[value as usize] = case_id;
             }
         }
-        &syn::Pat::Range(syn::PatRange { ref start, ref end, .. }) => {
-            let lo = get_byte_from_expr_lit(&start.as_ref().unwrap());
-            let hi = get_byte_from_expr_lit(&end.as_ref().unwrap());
+        syn::Pat::Range(syn::PatRange {
+            ref start, ref end, ..
+        }) => {
+            let lo = get_byte_from_expr_lit(start.as_ref().unwrap());
+            let hi = get_byte_from_expr_lit(end.as_ref().unwrap());
             for value in lo..hi {
                 if table[value as usize] == 0 {
                     table[value as usize] = case_id;
@@ -81,14 +81,14 @@ fn parse_pat_to_table<'a>(
                 table[hi as usize] = case_id;
             }
         }
-        &syn::Pat::Wild(_) => {
+        syn::Pat::Wild(_) => {
             for byte in table.iter_mut() {
                 if *byte == 0 {
                     *byte = case_id;
                 }
             }
         }
-        &syn::Pat::Ident(syn::PatIdent { ref ident, .. }) => {
+        syn::Pat::Ident(syn::PatIdent { ref ident, .. }) => {
             assert_eq!(*wildcard, None);
             *wildcard = Some(ident);
             for byte in table.iter_mut() {
@@ -97,7 +97,7 @@ fn parse_pat_to_table<'a>(
                 }
             }
         }
-        &syn::Pat::Or(syn::PatOr { ref cases, .. }) => {
+        syn::Pat::Or(syn::PatOr { ref cases, .. }) => {
             for case in cases {
                 parse_pat_to_table(case, case_id, wildcard, table);
             }
diff --git a/src/cow_rc_str.rs b/src/cow_rc_str.rs
index ecf14a0a..26508481 100644
--- a/src/cow_rc_str.rs
+++ b/src/cow_rc_str.rs
@@ -4,7 +4,7 @@
 
 use std::borrow::{Borrow, Cow};
 use std::rc::Rc;
-use std::{cmp, fmt, hash, marker, mem, ops, slice, str, ptr};
+use std::{cmp, fmt, hash, marker, mem, ops, ptr, slice, str};
 
 /// A string that is either shared (heap-allocated and reference-counted) or borrowed.
 ///
@@ -23,9 +23,9 @@ pub struct CowRcStr<'a> {
     phantom: marker::PhantomData<Result<&'a str, Rc<String>>>,
 }
 
-fn _static_assert_same_size<'a>() {
+fn _static_assert_same_size() {
     // "Instantiate" the generic function without calling it.
-    let _ = mem::transmute::<CowRcStr<'a>, Option<CowRcStr<'a>>>;
+    let _ = mem::transmute::<CowRcStr<'_>, Option<CowRcStr<'_>>>;
 }
 
 impl<'a> From<Cow<'a, str>> for CowRcStr<'a> {
diff --git a/src/macros.rs b/src/macros.rs
index fc4b77a1..67d83658 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -182,7 +182,7 @@ pub fn _cssparser_internal_to_lowercase<'a>(
         let input_bytes =
             unsafe { &*(input.as_bytes() as *const [u8] as *const [MaybeUninit<u8>]) };
 
-        buffer.copy_from_slice(&*input_bytes);
+        buffer.copy_from_slice(input_bytes);
 
         // Same as above re layout, plus these bytes have been initialized:
         let buffer = unsafe { &mut *(buffer as *mut [MaybeUninit<u8>] as *mut [u8]) };
@@ -195,7 +195,7 @@ pub fn _cssparser_internal_to_lowercase<'a>(
     }
 
     Some(
-        match input.bytes().position(|byte| matches!(byte, b'A'..=b'Z')) {
+        match input.bytes().position(|byte| byte.is_ascii_uppercase()) {
             Some(first_uppercase) => make_ascii_lowercase(buffer, input, first_uppercase),
             // common case: input is already lower-case
             None => input,
diff --git a/src/nth.rs b/src/nth.rs
index 518de4d9..e4bde0de 100644
--- a/src/nth.rs
+++ b/src/nth.rs
@@ -8,7 +8,7 @@ use super::{BasicParseError, Parser, ParserInput, Token};
 /// The input is typically the arguments of a function,
 /// in which case the caller needs to check if the arguments’ parser is exhausted.
 /// Return `Ok((A, B))`, or `Err(())` for a syntax error.
-pub fn parse_nth<'i, 't>(input: &mut Parser<'i, 't>) -> Result<(i32, i32), BasicParseError<'i>> {
+pub fn parse_nth<'i>(input: &mut Parser<'i, '_>) -> Result<(i32, i32), BasicParseError<'i>> {
     match *input.next()? {
         Token::Number {
             int_value: Some(b), ..
@@ -22,7 +22,7 @@ pub fn parse_nth<'i, 't>(input: &mut Parser<'i, 't>) -> Result<(i32, i32), Basic
                 unit,
                 "n" => Ok(parse_b(input, a)?),
                 "n-" => Ok(parse_signless_b(input, a, -1)?),
-                _ => match parse_n_dash_digits(&*unit) {
+                _ => match parse_n_dash_digits(unit) {
                     Ok(b) => Ok((a, b)),
                     Err(()) => {
                         let unit = unit.clone();
@@ -40,8 +40,8 @@ pub fn parse_nth<'i, 't>(input: &mut Parser<'i, 't>) -> Result<(i32, i32), Basic
                 "n-" => Ok(parse_signless_b(input, 1, -1)?),
                 "-n-" => Ok(parse_signless_b(input, -1, -1)?),
                 _ => {
-                    let (slice, a) = if value.starts_with("-") {
-                        (&value[1..], -1)
+                    let (slice, a) = if let Some(stripped) = value.strip_prefix('-') {
+                        (stripped, -1)
                     } else {
                         (&**value, 1)
                     };
@@ -81,7 +81,7 @@ pub fn parse_nth<'i, 't>(input: &mut Parser<'i, 't>) -> Result<(i32, i32), Basic
     }
 }
 
-fn parse_b<'i, 't>(input: &mut Parser<'i, 't>, a: i32) -> Result<(i32, i32), BasicParseError<'i>> {
+fn parse_b<'i>(input: &mut Parser<'i, '_>, a: i32) -> Result<(i32, i32), BasicParseError<'i>> {
     let start = input.state();
     match input.next() {
         Ok(&Token::Delim('+')) => parse_signless_b(input, a, 1),
@@ -98,8 +98,8 @@ fn parse_b<'i, 't>(input: &mut Parser<'i, 't>, a: i32) -> Result<(i32, i32), Bas
     }
 }
 
-fn parse_signless_b<'i, 't>(
-    input: &mut Parser<'i, 't>,
+fn parse_signless_b<'i>(
+    input: &mut Parser<'i, '_>,
     a: i32,
     b_sign: i32,
 ) -> Result<(i32, i32), BasicParseError<'i>> {
@@ -118,7 +118,7 @@ fn parse_n_dash_digits(string: &str) -> Result<i32, ()> {
     let bytes = string.as_bytes();
     if bytes.len() >= 3
         && bytes[..2].eq_ignore_ascii_case(b"n-")
-        && bytes[2..].iter().all(|&c| matches!(c, b'0'..=b'9'))
+        && bytes[2..].iter().all(|&c| c.is_ascii_digit())
     {
         Ok(parse_number_saturate(&string[1..]).unwrap()) // Include the minus sign
     } else {
diff --git a/src/parser.rs b/src/parser.rs
index dd7777a2..424306e1 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -116,7 +116,7 @@ impl<'i, T> From<BasicParseError<'i>> for ParseError<'i, T> {
 impl SourceLocation {
     /// Create a new BasicParseError at this location for an unexpected token
     #[inline]
-    pub fn new_basic_unexpected_token_error<'i>(self, token: Token<'i>) -> BasicParseError<'i> {
+    pub fn new_basic_unexpected_token_error(self, token: Token<'_>) -> BasicParseError<'_> {
         BasicParseError {
             kind: BasicParseErrorKind::UnexpectedToken(token),
             location: self,
@@ -125,7 +125,7 @@ impl SourceLocation {
 
     /// Create a new ParseError at this location for an unexpected token
     #[inline]
-    pub fn new_unexpected_token_error<'i, E>(self, token: Token<'i>) -> ParseError<'i, E> {
+    pub fn new_unexpected_token_error<E>(self, token: Token<'_>) -> ParseError<'_, E> {
         ParseError {
             kind: ParseErrorKind::Basic(BasicParseErrorKind::UnexpectedToken(token)),
             location: self,
@@ -652,9 +652,8 @@ impl<'i: 't, 't> Parser<'i, 't> {
         let token = if using_cached_token {
             let cached_token = self.input.cached_token.as_ref().unwrap();
             self.input.tokenizer.reset(&cached_token.end_state);
-            match cached_token.token {
-                Token::Function(ref name) => self.input.tokenizer.see_function(name),
-                _ => {}
+            if let Token::Function(ref name) = cached_token.token {
+                self.input.tokenizer.see_function(name)
             }
             &cached_token.token
         } else {
@@ -748,7 +747,7 @@ impl<'i: 't, 't> Parser<'i, 't> {
             match self.parse_until_before(Delimiter::Comma, &mut parse_one) {
                 Ok(v) => values.push(v),
                 Err(e) if !ignore_errors => return Err(e),
-                Err(_) => {},
+                Err(_) => {}
             }
             match self.next() {
                 Err(_) => return Ok(values),
@@ -835,7 +834,7 @@ impl<'i: 't, 't> Parser<'i, 't> {
     /// expect_ident, but clone the CowRcStr
     #[inline]
     pub fn expect_ident_cloned(&mut self) -> Result<CowRcStr<'i>, BasicParseError<'i>> {
-        self.expect_ident().map(|s| s.clone())
+        self.expect_ident().cloned()
     }
 
     /// Parse a <ident-token> whose unescaped value is an ASCII-insensitive match for the given value.
@@ -860,7 +859,7 @@ impl<'i: 't, 't> Parser<'i, 't> {
     /// expect_string, but clone the CowRcStr
     #[inline]
     pub fn expect_string_cloned(&mut self) -> Result<CowRcStr<'i>, BasicParseError<'i>> {
-        self.expect_string().map(|s| s.clone())
+        self.expect_string().cloned()
     }
 
     /// Parse either a <ident-token> or a <string-token>, and return the unescaped value.
@@ -879,7 +878,7 @@ impl<'i: 't, 't> Parser<'i, 't> {
             Token::UnquotedUrl(ref value) => Ok(value.clone()),
             Token::Function(ref name) if name.eq_ignore_ascii_case("url") => {
                 self.parse_nested_block(|input| {
-                    input.expect_string().map_err(Into::into).map(|s| s.clone())
+                    input.expect_string().map_err(Into::into).cloned()
                 })
                 .map_err(ParseError::<()>::basic)
             }
@@ -894,7 +893,7 @@ impl<'i: 't, 't> Parser<'i, 't> {
             Token::QuotedString(ref value) => Ok(value.clone()),
             Token::Function(ref name) if name.eq_ignore_ascii_case("url") => {
                 self.parse_nested_block(|input| {
-                    input.expect_string().map_err(Into::into).map(|s| s.clone())
+                    input.expect_string().map_err(Into::into).cloned()
                 })
                 .map_err(ParseError::<()>::basic)
             }
diff --git a/src/rules_and_declarations.rs b/src/rules_and_declarations.rs
index fb33a7d0..b23e9dc0 100644
--- a/src/rules_and_declarations.rs
+++ b/src/rules_and_declarations.rs
@@ -14,7 +14,7 @@ use crate::parser::{parse_nested_block, parse_until_after, ParseUntilErrorBehavi
 ///
 /// Typical usage is `input.try_parse(parse_important).is_ok()`
 /// at the end of a `DeclarationParser::parse_value` implementation.
-pub fn parse_important<'i, 't>(input: &mut Parser<'i, 't>) -> Result<(), BasicParseError<'i>> {
+pub fn parse_important<'i>(input: &mut Parser<'i, '_>) -> Result<(), BasicParseError<'i>> {
     input.expect_delim('!')?;
     input.expect_ident_matching("important")
 }
@@ -253,10 +253,10 @@ where
             self.input.skip_whitespace();
             let start = self.input.state();
             match self.input.next_including_whitespace_and_comments().ok()? {
-                Token::CloseCurlyBracket |
-                Token::WhiteSpace(..) |
-                Token::Semicolon |
-                Token::Comment(..) => continue,
+                Token::CloseCurlyBracket
+                | Token::WhiteSpace(..)
+                | Token::Semicolon
+                | Token::Comment(..) => continue,
                 Token::AtKeyword(ref name) => {
                     let name = name.clone();
                     return Some(parse_at_rule(&start, name, self.input, &mut *self.parser));
@@ -294,7 +294,7 @@ where
                             &mut *self.parser,
                             Delimiter::Semicolon | Delimiter::CurlyBracketBlock,
                         ) {
-                            return Some(Ok(qual))
+                            return Some(Ok(qual));
                         }
                     }
 
@@ -367,7 +367,7 @@ where
             let start = self.input.state();
             let at_keyword = match self.input.next_byte()? {
                 b'@' => match self.input.next_including_whitespace_and_comments() {
-                    Ok(&Token::AtKeyword(ref name)) => Some(name.clone()),
+                    Ok(Token::AtKeyword(name)) => Some(name.clone()),
                     _ => {
                         self.input.reset(&start);
                         None
@@ -503,5 +503,5 @@ where
     input.expect_curly_bracket_block()?;
     // Do this here so that we consume the `{` even if the prelude is `Err`.
     let prelude = prelude?;
-    parse_nested_block(input, |input| parser.parse_block(prelude, &start, input))
+    parse_nested_block(input, |input| parser.parse_block(prelude, start, input))
 }
diff --git a/src/serializer.rs b/src/serializer.rs
index 09c22402..403976cd 100644
--- a/src/serializer.rs
+++ b/src/serializer.rs
@@ -3,8 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use crate::match_byte;
-use dtoa_short::{self, Notation};
-use itoa;
+use dtoa_short::Notation;
 use std::fmt::{self, Write};
 use std::str;
 
@@ -49,10 +48,9 @@ where
         dtoa_short::write(dest, value)?
     };
 
-    if int_value.is_none() && value.fract() == 0. {
-        if !notation.decimal_point && !notation.scientific {
-            dest.write_str(".0")?;
-        }
+    if int_value.is_none() && value.fract() == 0. && !notation.decimal_point && !notation.scientific
+    {
+        dest.write_str(".0")?;
     }
     Ok(())
 }
@@ -63,10 +61,10 @@ impl<'a> ToCss for Token<'a> {
         W: fmt::Write,
     {
         match *self {
-            Token::Ident(ref value) => serialize_identifier(&**value, dest)?,
+            Token::Ident(ref value) => serialize_identifier(value, dest)?,
             Token::AtKeyword(ref value) => {
                 dest.write_str("@")?;
-                serialize_identifier(&**value, dest)?;
+                serialize_identifier(value, dest)?;
             }
             Token::Hash(ref value) => {
                 dest.write_str("#")?;
@@ -74,12 +72,12 @@ impl<'a> ToCss for Token<'a> {
             }
             Token::IDHash(ref value) => {
                 dest.write_str("#")?;
-                serialize_identifier(&**value, dest)?;
+                serialize_identifier(value, dest)?;
             }
-            Token::QuotedString(ref value) => serialize_string(&**value, dest)?,
+            Token::QuotedString(ref value) => serialize_string(value, dest)?,
             Token::UnquotedUrl(ref value) => {
                 dest.write_str("url(")?;
-                serialize_unquoted_url(&**value, dest)?;
+                serialize_unquoted_url(value, dest)?;
                 dest.write_str(")")?;
             }
             Token::Delim(value) => dest.write_char(value)?,
@@ -134,7 +132,7 @@ impl<'a> ToCss for Token<'a> {
             Token::CDC => dest.write_str("-->")?,
 
             Token::Function(ref name) => {
-                serialize_identifier(&**name, dest)?;
+                serialize_identifier(name, dest)?;
                 dest.write_str("(")?;
             }
             Token::ParenthesisBlock => dest.write_str("(")?,
@@ -167,7 +165,7 @@ fn hex_escape<W>(ascii_byte: u8, dest: &mut W) -> fmt::Result
 where
     W: fmt::Write,
 {
-    static HEX_DIGITS: &'static [u8; 16] = b"0123456789abcdef";
+    static HEX_DIGITS: &[u8; 16] = b"0123456789abcdef";
     let b3;
     let b4;
     let bytes = if ascii_byte > 0x0F {
@@ -179,7 +177,7 @@ where
         b3 = [b'\\', HEX_DIGITS[ascii_byte as usize], b' '];
         &b3[..]
     };
-    dest.write_str(unsafe { str::from_utf8_unchecked(&bytes) })
+    dest.write_str(unsafe { str::from_utf8_unchecked(bytes) })
 }
 
 fn char_escape<W>(ascii_byte: u8, dest: &mut W) -> fmt::Result
@@ -199,9 +197,9 @@ where
         return Ok(());
     }
 
-    if value.starts_with("--") {
+    if let Some(value) = value.strip_prefix("--") {
         dest.write_str("--")?;
-        serialize_name(&value[2..], dest)
+        serialize_name(value, dest)
     } else if value == "-" {
         dest.write_str("\\-")
     } else {
@@ -240,7 +238,7 @@ where
         dest.write_str(&value[chunk_start..i])?;
         if let Some(escaped) = escaped {
             dest.write_str(escaped)?;
-        } else if (b >= b'\x01' && b <= b'\x1F') || b == b'\x7F' {
+        } else if (b'\x01'..=b'\x1F').contains(&b) || b == b'\x7F' {
             hex_escape(b, dest)?;
         } else {
             char_escape(b, dest)?;
diff --git a/src/tests.rs b/src/tests.rs
index f9dea193..98c51f61 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -5,8 +5,7 @@
 #[cfg(feature = "bench")]
 extern crate test;
 
-use encoding_rs;
-use serde_json::{self, json, Map, Value};
+use serde_json::{json, Map, Value};
 
 #[cfg(feature = "bench")]
 use self::test::Bencher;
@@ -25,25 +24,23 @@ macro_rules! JArray {
 }
 
 fn almost_equals(a: &Value, b: &Value) -> bool {
-    match (a, b) {
-        (&Value::Number(ref a), &Value::Number(ref b)) => {
+    let var_name = match (a, b) {
+        (Value::Number(a), Value::Number(b)) => {
             let a = a.as_f64().unwrap();
             let b = b.as_f64().unwrap();
             (a - b).abs() <= a.abs() * 1e-6
         }
 
         (&Value::Bool(a), &Value::Bool(b)) => a == b,
-        (&Value::String(ref a), &Value::String(ref b)) => a == b,
-        (&Value::Array(ref a), &Value::Array(ref b)) => {
-            a.len() == b.len()
-                && a.iter()
-                    .zip(b.iter())
-                    .all(|(ref a, ref b)| almost_equals(*a, *b))
+        (Value::String(a), Value::String(b)) => a == b,
+        (Value::Array(a), Value::Array(b)) => {
+            a.len() == b.len() && a.iter().zip(b.iter()).all(|(a, b)| almost_equals(a, b))
         }
         (&Value::Object(_), &Value::Object(_)) => panic!("Not implemented"),
         (&Value::Null, &Value::Null) => true,
         _ => false,
-    }
+    };
+    var_name
 }
 
 fn normalize(json: &mut Value) {
@@ -77,7 +74,7 @@ fn assert_json_eq(results: Value, mut expected: Value, message: &str) {
     }
 }
 
-fn run_raw_json_tests<F: Fn(Value, Value) -> ()>(json_data: &str, run: F) {
+fn run_raw_json_tests<F: Fn(Value, Value)>(json_data: &str, run: F) {
     let items = match serde_json::from_str(json_data) {
         Ok(Value::Array(items)) => items,
         other => panic!("Invalid JSON: {:?}", other),
@@ -242,7 +239,7 @@ fn stylesheet_from_bytes() {
 
     fn get_string<'a>(map: &'a Map<String, Value>, key: &str) -> Option<&'a str> {
         match map.get(key) {
-            Some(&Value::String(ref s)) => Some(s),
+            Some(Value::String(s)) => Some(s),
             Some(&Value::Null) => None,
             None => None,
             _ => panic!("Unexpected JSON"),
@@ -393,7 +390,7 @@ fn unicode_range() {
             if input.is_exhausted() {
                 Ok(result)
             } else {
-                while let Ok(_) = input.next() {}
+                while input.next().is_ok() {}
                 Ok(None)
             }
         });
@@ -593,8 +590,6 @@ fn line_numbers() {
 
 #[test]
 fn overflow() {
-    use std::iter::repeat;
-
     let css = r"
          2147483646
          2147483647
@@ -619,7 +614,7 @@ fn overflow() {
          -3.402824e+38
 
     "
-    .replace("{309 zeros}", &repeat('0').take(309).collect::<String>());
+    .replace("{309 zeros}", &"0".repeat(309));
     let mut input = ParserInput::new(&css);
     let mut input = Parser::new(&mut input);
 
@@ -637,15 +632,13 @@ fn overflow() {
     assert_eq!(input.expect_integer(), Ok(-2147483648));
     assert_eq!(input.expect_integer(), Ok(-2147483648));
 
-    assert_eq!(input.expect_number(), Ok(3.30282347e+38));
+    assert_eq!(input.expect_number(), Ok(3.302_823_5e38));
     assert_eq!(input.expect_number(), Ok(f32::MAX));
     assert_eq!(input.expect_number(), Ok(f32::INFINITY));
-    assert!(f32::MAX != f32::INFINITY);
 
-    assert_eq!(input.expect_number(), Ok(-3.30282347e+38));
+    assert_eq!(input.expect_number(), Ok(-3.302_823_5e38));
     assert_eq!(input.expect_number(), Ok(f32::MIN));
     assert_eq!(input.expect_number(), Ok(f32::NEG_INFINITY));
-    assert!(f32::MIN != f32::NEG_INFINITY);
 }
 
 #[test]
@@ -784,7 +777,7 @@ where
 
 impl<'a> ToJson for CowRcStr<'a> {
     fn to_json(&self) -> Value {
-        let s: &str = &*self;
+        let s: &str = self;
         s.to_json()
     }
 }
@@ -847,7 +840,7 @@ fn no_stack_overflow_multiple_nested_blocks() {
     }
     let mut input = ParserInput::new(&input);
     let mut input = Parser::new(&mut input);
-    while let Ok(..) = input.next() {}
+    while input.next().is_ok() {}
 }
 
 impl<'i> DeclarationParser<'i> for JsonParser {
@@ -870,11 +863,9 @@ impl<'i> DeclarationParser<'i> for JsonParser {
                 // (even CSS Variables forbid top-level `!`)
                 if token == Token::Delim('!') {
                     input.reset(&start);
-                    if parse_important(input).is_ok() {
-                        if input.is_exhausted() {
-                            important = true;
-                            break;
-                        }
+                    if parse_important(input).is_ok() && input.is_exhausted() {
+                        important = true;
+                        break;
                     }
                     input.reset(&start);
                     token = input.next_including_whitespace().unwrap().clone();
@@ -905,7 +896,7 @@ impl<'i> AtRuleParser<'i> for JsonParser {
         ];
         match_ignore_ascii_case! { &*name,
             "charset" => {
-                Err(input.new_error(BasicParseErrorKind::AtRuleInvalid(name.clone()).into()))
+                Err(input.new_error(BasicParseErrorKind::AtRuleInvalid(name.clone())))
             },
             _ => Ok(prelude),
         }
@@ -978,9 +969,9 @@ fn one_component_value_to_json(token: Token, input: &mut Parser) -> Value {
     fn numeric(value: f32, int_value: Option<i32>, has_sign: bool) -> Vec<Value> {
         vec![
             Token::Number {
-                value: value,
-                int_value: int_value,
-                has_sign: has_sign,
+                value,
+                int_value,
+                has_sign,
             }
             .to_css_string()
             .to_json(),
@@ -1137,7 +1128,7 @@ fn parse_until_before_stops_at_delimiter_or_end_of_input() {
                             let ox = ix.next();
                             let oy = iy.next();
                             assert_eq!(ox, oy);
-                            if let Err(_) = ox {
+                            if ox.is_err() {
                                 break;
                             }
                         }
@@ -1223,7 +1214,7 @@ fn parse_sourcemapping_comments() {
     for test in tests {
         let mut input = ParserInput::new(test.0);
         let mut parser = Parser::new(&mut input);
-        while let Ok(_) = parser.next_including_whitespace() {}
+        while parser.next_including_whitespace().is_ok() {}
         assert_eq!(parser.current_source_map_url(), test.1);
     }
 }
@@ -1247,7 +1238,7 @@ fn parse_sourceurl_comments() {
     for test in tests {
         let mut input = ParserInput::new(test.0);
         let mut parser = Parser::new(&mut input);
-        while let Ok(_) = parser.next_including_whitespace() {}
+        while parser.next_including_whitespace().is_ok() {}
         assert_eq!(parser.current_source_url(), test.1);
     }
 }
@@ -1321,7 +1312,8 @@ fn utf16_columns() {
                     break;
                 }
                 Err(_) => {
-                    assert!(false);
+                    // should this be an explicit panic instead?
+                    unreachable!();
                 }
                 Ok(_) => {}
             };
diff --git a/src/tokenizer.rs b/src/tokenizer.rs
index a3b70063..f1716c71 100644
--- a/src/tokenizer.rs
+++ b/src/tokenizer.rs
@@ -255,10 +255,10 @@ impl<'a> Tokenizer<'a> {
 
     #[inline]
     pub fn see_function(&mut self, name: &str) {
-        if self.var_or_env_functions == SeenStatus::LookingForThem {
-            if name.eq_ignore_ascii_case("var") || name.eq_ignore_ascii_case("env") {
-                self.var_or_env_functions = SeenStatus::SeenAtLeastOne;
-            }
+        if self.var_or_env_functions == SeenStatus::LookingForThem
+            && (name.eq_ignore_ascii_case("var") || name.eq_ignore_ascii_case("env"))
+        {
+            self.var_or_env_functions = SeenStatus::SeenAtLeastOne;
         }
     }
 
@@ -322,10 +322,12 @@ impl<'a> Tokenizer<'a> {
 
     pub fn current_source_line(&self) -> &'a str {
         let current = self.position();
-        let start = self.slice(SourcePosition(0)..current)
+        let start = self
+            .slice(SourcePosition(0)..current)
             .rfind(|c| matches!(c, '\r' | '\n' | '\x0C'))
             .map_or(0, |start| start + 1);
-        let end = self.slice(current..SourcePosition(self.input.len()))
+        let end = self
+            .slice(current..SourcePosition(self.input.len()))
             .find(|c| matches!(c, '\r' | '\n' | '\x0C'))
             .map_or(self.input.len(), |end| current.0 + end);
         self.slice(SourcePosition(start)..SourcePosition(end))
@@ -424,7 +426,10 @@ impl<'a> Tokenizer<'a> {
 
     #[inline]
     fn next_char(&self) -> char {
-        unsafe { self.input.get_unchecked(self.position().0..) }.chars().next().unwrap()
+        unsafe { self.input.get_unchecked(self.position().0..) }
+            .chars()
+            .next()
+            .unwrap()
     }
 
     // Given that a newline has been seen, advance over the newline
@@ -582,11 +587,11 @@ fn next_token<'a>(tokenizer: &mut Tokenizer<'a>) -> Result<Token<'a>, ()> {
         b'+' => {
             if (
                 tokenizer.has_at_least(1)
-                && matches!(tokenizer.byte_at(1), b'0'..=b'9')
+                && tokenizer.byte_at(1).is_ascii_digit()
             ) || (
                 tokenizer.has_at_least(2)
                 && tokenizer.byte_at(1) == b'.'
-                && matches!(tokenizer.byte_at(2), b'0'..=b'9')
+                && tokenizer.byte_at(2).is_ascii_digit()
             ) {
                 consume_numeric(tokenizer)
             } else {
@@ -598,11 +603,11 @@ fn next_token<'a>(tokenizer: &mut Tokenizer<'a>) -> Result<Token<'a>, ()> {
         b'-' => {
             if (
                 tokenizer.has_at_least(1)
-                && matches!(tokenizer.byte_at(1), b'0'..=b'9')
+                && tokenizer.byte_at(1).is_ascii_digit()
             ) || (
                 tokenizer.has_at_least(2)
                 && tokenizer.byte_at(1) == b'.'
-                && matches!(tokenizer.byte_at(2), b'0'..=b'9')
+                && tokenizer.byte_at(2).is_ascii_digit()
             ) {
                 consume_numeric(tokenizer)
             } else if tokenizer.starts_with(b"-->") {
@@ -617,8 +622,7 @@ fn next_token<'a>(tokenizer: &mut Tokenizer<'a>) -> Result<Token<'a>, ()> {
         },
         b'.' => {
             if tokenizer.has_at_least(1)
-                && matches!(tokenizer.byte_at(1), b'0'..=b'9'
-            ) {
+                && tokenizer.byte_at(1).is_ascii_digit() {
                 consume_numeric(tokenizer)
             } else {
                 tokenizer.advance(1);
@@ -1001,7 +1005,7 @@ fn byte_to_hex_digit(b: u8) -> Option<u32> {
 }
 
 fn byte_to_decimal_digit(b: u8) -> Option<u32> {
-    if b >= b'0' && b <= b'9' {
+    if b.is_ascii_digit() {
         Some((b - b'0') as u32)
     } else {
         None
@@ -1038,7 +1042,7 @@ fn consume_numeric<'a>(tokenizer: &mut Tokenizer<'a>) -> Token<'a> {
     let mut fractional_part: f64 = 0.;
     if tokenizer.has_at_least(1)
         && tokenizer.next_byte_unchecked() == b'.'
-        && matches!(tokenizer.byte_at(1), b'0'..=b'9')
+        && tokenizer.byte_at(1).is_ascii_digit()
     {
         is_integer = false;
         tokenizer.advance(1); // Consume '.'
@@ -1055,32 +1059,32 @@ fn consume_numeric<'a>(tokenizer: &mut Tokenizer<'a>) -> Token<'a> {
 
     let mut value = sign * (integral_part + fractional_part);
 
-    if tokenizer.has_at_least(1) && matches!(tokenizer.next_byte_unchecked(), b'e' | b'E') {
-        if matches!(tokenizer.byte_at(1), b'0'..=b'9')
+    if tokenizer.has_at_least(1)
+        && matches!(tokenizer.next_byte_unchecked(), b'e' | b'E')
+        && (tokenizer.byte_at(1).is_ascii_digit()
             || (tokenizer.has_at_least(2)
                 && matches!(tokenizer.byte_at(1), b'+' | b'-')
-                && matches!(tokenizer.byte_at(2), b'0'..=b'9'))
-        {
-            is_integer = false;
+                && tokenizer.byte_at(2).is_ascii_digit()))
+    {
+        is_integer = false;
+        tokenizer.advance(1);
+        let (has_sign, sign) = match tokenizer.next_byte_unchecked() {
+            b'-' => (true, -1.),
+            b'+' => (true, 1.),
+            _ => (false, 1.),
+        };
+        if has_sign {
             tokenizer.advance(1);
-            let (has_sign, sign) = match tokenizer.next_byte_unchecked() {
-                b'-' => (true, -1.),
-                b'+' => (true, 1.),
-                _ => (false, 1.),
-            };
-            if has_sign {
-                tokenizer.advance(1);
-            }
-            let mut exponent: f64 = 0.;
-            while let Some(digit) = byte_to_decimal_digit(tokenizer.next_byte_unchecked()) {
-                exponent = exponent * 10. + digit as f64;
-                tokenizer.advance(1);
-                if tokenizer.is_eof() {
-                    break;
-                }
+        }
+        let mut exponent: f64 = 0.;
+        while let Some(digit) = byte_to_decimal_digit(tokenizer.next_byte_unchecked()) {
+            exponent = exponent * 10. + digit as f64;
+            tokenizer.advance(1);
+            if tokenizer.is_eof() {
+                break;
             }
-            value *= f64::powf(10., sign * exponent);
         }
+        value *= f64::powf(10., sign * exponent);
     }
 
     let int_value = if is_integer {
@@ -1339,7 +1343,7 @@ fn consume_unquoted_url<'a>(tokenizer: &mut Tokenizer<'a>) -> Result<Token<'a>,
 }
 
 // (value, number of digits up to 6)
-fn consume_hex_digits<'a>(tokenizer: &mut Tokenizer<'a>) -> (u32, u32) {
+fn consume_hex_digits(tokenizer: &mut Tokenizer<'_>) -> (u32, u32) {
     let mut value = 0;
     let mut digits = 0;
     while digits < 6 && !tokenizer.is_eof() {
diff --git a/src/unicode_range.rs b/src/unicode_range.rs
index b0a2017c..ce6bb3b5 100644
--- a/src/unicode_range.rs
+++ b/src/unicode_range.rs
@@ -24,7 +24,7 @@ pub struct UnicodeRange {
 
 impl UnicodeRange {
     /// https://drafts.csswg.org/css-syntax/#urange-syntax
-    pub fn parse<'i, 't>(input: &mut Parser<'i, 't>) -> Result<Self, BasicParseError<'i>> {
+    pub fn parse<'i>(input: &mut Parser<'i, '_>) -> Result<Self, BasicParseError<'i>> {
         // <urange> =
         //   u '+' <ident-token> '?'* |
         //   u <dimension-token> '?'* |
@@ -57,7 +57,7 @@ impl UnicodeRange {
     }
 }
 
-fn parse_tokens<'i, 't>(input: &mut Parser<'i, 't>) -> Result<(), BasicParseError<'i>> {
+fn parse_tokens<'i>(input: &mut Parser<'i, '_>) -> Result<(), BasicParseError<'i>> {
     match input.next_including_whitespace()?.clone() {
         Token::Delim('+') => {
             match *input.next_including_whitespace()? {
@@ -123,15 +123,13 @@ fn parse_concatenated(text: &[u8]) -> Result<UnicodeRange, ()> {
             start: first_hex_value,
             end: first_hex_value,
         });
-    } else {
-        if let Some((&b'-', mut text)) = text.split_first() {
-            let (second_hex_value, hex_digit_count) = consume_hex(&mut text);
-            if hex_digit_count > 0 && hex_digit_count <= 6 && text.is_empty() {
-                return Ok(UnicodeRange {
-                    start: first_hex_value,
-                    end: second_hex_value,
-                });
-            }
+    } else if let Some((&b'-', mut text)) = text.split_first() {
+        let (second_hex_value, hex_digit_count) = consume_hex(&mut text);
+        if hex_digit_count > 0 && hex_digit_count <= 6 && text.is_empty() {
+            return Ok(UnicodeRange {
+                start: first_hex_value,
+                end: second_hex_value,
+            });
         }
     }
     Err(())