Fix clippy warnings.

src/ggg/lookup.rs

@@ -70,6 +70,11 @@ impl<'a> LookupSubtables<'a> {
         self.offsets.len()
     }
 
+    /// Checks if there are any items.
+    pub fn is_empty(&self) -> bool {
+        self.offsets.is_empty()
+    }
+
     /// Parses a subtable at index.
     ///
     /// Accepts either
@@ -86,6 +91,7 @@ impl<'a> LookupSubtables<'a> {
     /// Creates an iterator over subtables.
     ///
     /// We cannot use `IntoIterator` here, because we have to use user-provided base type.
+    #[allow(clippy::should_implement_trait)]
     pub fn into_iter<T: LookupSubtable<'a>>(self) -> LookupSubtablesIter<'a, T> {
         LookupSubtablesIter {
             data: self,

src/lib.rs

@@ -38,6 +38,12 @@ Font parsing starts with a [`Face`].
 #![warn(missing_docs)]
 #![warn(missing_copy_implementations)]
 #![warn(missing_debug_implementations)]
+#![allow(clippy::get_first)] // we use it for readability
+#![allow(clippy::identity_op)] // we use it for readability
+#![allow(clippy::too_many_arguments)]
+#![allow(clippy::collapsible_else_if)]
+#![allow(clippy::field_reassign_with_default)]
+#![allow(clippy::upper_case_acronyms)]
 
 #[cfg(feature = "std")]
 #[macro_use]
@@ -144,7 +150,7 @@ impl FromData for Magic {
 ///
 /// The number is stored as f2.16
 #[repr(transparent)]
-#[derive(Clone, Copy, PartialEq, Default, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Default, Debug)]
 pub struct NormalizedCoordinate(i16);
 
 impl From<i16> for NormalizedCoordinate {
@@ -305,7 +311,7 @@ impl FromData for Tag {
 ///
 /// Used for underline and strikeout.
 #[repr(C)]
-#[derive(Clone, Copy, PartialEq, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub struct LineMetrics {
     /// Line position.
     pub position: i16,
@@ -319,7 +325,7 @@ pub struct LineMetrics {
 /// Doesn't guarantee that `x_min` <= `x_max` and/or `y_min` <= `y_max`.
 #[repr(C)]
 #[allow(missing_docs)]
-#[derive(Clone, Copy, PartialEq, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub struct Rect {
     pub x_min: i16,
     pub y_min: i16,
@@ -377,7 +383,7 @@ impl BBox {
     }
 
     #[inline]
-    fn to_rect(&self) -> Option<Rect> {
+    fn to_rect(self) -> Option<Rect> {
         Some(Rect {
             x_min: i16::try_num_from(self.x_min)?,
             y_min: i16::try_num_from(self.y_min)?,
@@ -420,15 +426,15 @@ impl OutlineBuilder for DummyOutline {
 
 /// A glyph raster image format.
 #[allow(missing_docs)]
-#[derive(Clone, Copy, PartialEq, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub enum RasterImageFormat {
     PNG,
 }
 
 /// A glyph's raster image.
 ///
 /// Note, that glyph metrics are in pixels and not in font units.
-#[derive(Clone, Copy, PartialEq, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub struct RasterGlyphImage<'a> {
     /// Horizontal offset.
     pub x: i16,
@@ -507,7 +513,7 @@ impl VarCoords {
 }
 
 /// A list of font face parsing errors.
-#[derive(Clone, Copy, PartialEq, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub enum FaceParsingError {
     /// An attempt to read out of bounds detected.
     ///

src/parser.rs

@@ -124,7 +124,7 @@ pub struct F2DOT14(pub i16);
 impl F2DOT14 {
     /// Converts i16 to f32.
     #[inline]
-    pub fn to_f32(&self) -> f32 {
+    pub fn to_f32(self) -> f32 {
         f32::from(self.0) / 16384.0
     }
 }
@@ -213,6 +213,7 @@ impl TryNumFrom<f32> for u16 {
     }
 }
 
+#[allow(clippy::manual_range_contains)]
 impl TryNumFrom<f32> for i32 {
     #[inline]
     fn try_num_from(v: f32) -> Option<Self> {
@@ -403,7 +404,7 @@ impl<'a, T: FromData> Iterator for LazyArrayIter16<'a, T> {
 
     #[inline]
     fn count(self) -> usize {
-        usize::from(self.data.len().checked_sub(self.index).unwrap_or(0))
+        usize::from(self.data.len().saturating_sub(self.index))
     }
 }
 
@@ -454,6 +455,11 @@ impl<'a, T: FromData> LazyArray32<'a, T> {
         (self.data.len() / T::SIZE) as u32
     }
 
+    /// Checks if the array is empty.
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     /// Performs a binary search by specified `key`.
     #[inline]
     pub fn binary_search(&self, key: &T) -> Option<(u32, T)>
@@ -538,7 +544,7 @@ impl<'a, T: FromData> Iterator for LazyArrayIter32<'a, T> {
 
     #[inline]
     fn count(self) -> usize {
-        usize::num_from(self.data.len().checked_sub(self.index).unwrap_or(0))
+        usize::num_from(self.data.len().saturating_sub(self.index))
     }
 }
 
@@ -641,12 +647,12 @@ impl<'a, T: FromSlice<'a>> Iterator for LazyOffsetArrayIter16<'a, T> {
 
     #[inline]
     fn count(self) -> usize {
-        usize::from(self.array.len().checked_sub(self.index).unwrap_or(0))
+        usize::from(self.array.len().saturating_sub(self.index))
     }
 }
 
 /// A streaming binary parser.
-#[derive(Clone, Copy, Default, Debug)]
+#[derive(Clone, Default, Debug)]
 pub struct Stream<'a> {
     data: &'a [u8],
     offset: usize,

src/tables/ankr.rs

@@ -9,7 +9,7 @@ use crate::GlyphId;
 
 /// An anchor point.
 #[allow(missing_docs)]
-#[derive(Clone, Copy, PartialEq, Default, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Default, Debug)]
 pub struct Point {
     pub x: i16,
     pub y: i16,

src/tables/avar.rs

@@ -45,6 +45,11 @@ impl<'a> SegmentMaps<'a> {
     pub fn len(&self) -> u16 {
         self.count
     }
+
+    /// Checks if there are any segments.
+    pub fn is_empty(&self) -> bool {
+        self.count == 0
+    }
 }
 
 impl core::fmt::Debug for SegmentMaps<'_> {
@@ -76,7 +81,7 @@ impl<'a> Iterator for SegmentMapsIter<'a> {
 
     fn next(&mut self) -> Option<Self::Item> {
         let count = self.stream.read::<u16>()?;
-        return self.stream.read_array16::<AxisValueMap>(count);
+        self.stream.read_array16::<AxisValueMap>(count)
     }
 }
 
@@ -126,7 +131,7 @@ impl<'a> Table<'a> {
 fn map_value(map: &LazyArray16<AxisValueMap>, value: i16) -> Option<i16> {
     // This code is based on harfbuzz implementation.
 
-    if map.len() == 0 {
+    if map.is_empty() {
         return Some(value);
     } else if map.len() == 1 {
         let record = map.get(0)?;

src/tables/cff/cff1.rs

@@ -784,7 +784,7 @@ impl FDSelect<'_> {
     fn font_dict_index(&self, glyph_id: GlyphId) -> Option<u8> {
         match self {
             FDSelect::Format0(ref array) => array.get(glyph_id.0),
-            FDSelect::Format3(ref data) => {
+            FDSelect::Format3(data) => {
                 let mut s = Stream::new(data);
                 let number_of_ranges = s.read::<u16>()?;
                 if number_of_ranges == 0 {
@@ -842,20 +842,17 @@ fn parse_sid_metadata<'a>(
     metadata.default_width = private_dict.default_width.unwrap_or(0.0);
     metadata.nominal_width = private_dict.nominal_width.unwrap_or(0.0);
 
-    match (
+    if let (Some(private_dict_range), Some(subroutines_offset)) = (
         top_dict.private_dict_range,
         private_dict.local_subroutines_offset,
     ) {
-        (Some(private_dict_range), Some(subroutines_offset)) => {
-            // 'The local subroutines offset is relative to the beginning
-            // of the Private DICT data.'
-            if let Some(start) = private_dict_range.start.checked_add(subroutines_offset) {
-                let data = data.get(start..data.len())?;
-                let mut s = Stream::new(data);
-                metadata.local_subrs = parse_index::<u16>(&mut s)?;
-            }
+        // 'The local subroutines offset is relative to the beginning
+        // of the Private DICT data.'
+        if let Some(start) = private_dict_range.start.checked_add(subroutines_offset) {
+            let data = data.get(start..data.len())?;
+            let mut s = Stream::new(data);
+            metadata.local_subrs = parse_index::<u16>(&mut s)?;
         }
-        _ => {}
     }
 
     Some(FontKind::SID(metadata))

src/tables/cff/index.rs

@@ -31,7 +31,7 @@ fn parse_index_impl<'a>(count: u32, s: &mut Stream<'a>) -> Option<Index<'a>> {
     let offset_size = s.read::<OffsetSize>()?;
     let offsets_len = (count + 1).checked_mul(offset_size.to_u32())?;
     let offsets = VarOffsets {
-        data: &s.read_bytes(usize::num_from(offsets_len))?,
+        data: s.read_bytes(usize::num_from(offsets_len))?,
         offset_size,
     };
 
@@ -60,7 +60,7 @@ fn skip_index_impl(count: u32, s: &mut Stream) -> Option<()> {
     let offset_size = s.read::<OffsetSize>()?;
     let offsets_len = (count + 1).checked_mul(offset_size.to_u32())?;
     let offsets = VarOffsets {
-        data: &s.read_bytes(usize::num_from(offsets_len))?,
+        data: s.read_bytes(usize::num_from(offsets_len))?,
         offset_size,
     };
 
@@ -153,7 +153,7 @@ impl<'a> Index<'a> {
     #[inline]
     pub fn len(&self) -> u32 {
         // Last offset points to the byte after the `Object data`. We should skip it.
-        self.offsets.len().checked_sub(1).unwrap_or(0)
+        self.offsets.len().saturating_sub(1)
     }
 
     pub fn get(&self, index: u32) -> Option<&'a [u8]> {
@@ -184,7 +184,7 @@ impl<'a> Iterator for IndexIter<'a> {
     }
 }
 
-#[derive(Clone, Copy, PartialEq, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub enum OffsetSize {
     Size1 = 1,
     Size2 = 2,

src/tables/cff/mod.rs

@@ -17,7 +17,7 @@ use crate::{BBox, OutlineBuilder};
 
 /// A list of errors that can occur during a CFF glyph outlining.
 #[allow(missing_docs)]
-#[derive(Clone, Copy, PartialEq, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub enum CFFError {
     NoGlyph,
     ReadOutOfBounds,
@@ -75,7 +75,7 @@ impl<'a> Builder<'a> {
 }
 
 /// A type-safe wrapper for string ID.
-#[derive(Clone, Copy, PartialEq, PartialOrd, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Debug)]
 pub struct StringId(u16);
 
 impl FromData for StringId {

src/tables/cmap/format12.rs

@@ -62,7 +62,7 @@ impl<'a> Subtable12<'a> {
             .start_glyph_id
             .checked_add(code_point)?
             .checked_sub(group.start_char_code)?;
-        return u16::try_from(id).ok().map(GlyphId);
+        u16::try_from(id).ok().map(GlyphId)
     }
 
     /// Calls `f` for each codepoint defined in this table.

src/tables/cmap/format14.rs

@@ -69,7 +69,7 @@ impl FromData for UnicodeRangeRecord {
 }
 
 /// A result of a variation glyph mapping.
-#[derive(Clone, Copy, PartialEq, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub enum GlyphVariationResult {
     /// Glyph was found in the variation encoding table.
     Found(GlyphId),

src/tables/cmap/mod.rs

@@ -216,11 +216,16 @@ impl<'a> Subtables<'a> {
         })
     }
 
-    /// Returns the number
+    /// Returns the number of subtables.
     #[inline]
     pub fn len(&self) -> u16 {
         self.records.len()
     }
+
+    /// Checks if there are any subtables.
+    pub fn is_empty(&self) -> bool {
+        self.records.is_empty()
+    }
 }
 
 impl<'a> IntoIterator for Subtables<'a> {

src/tables/feat.rs

@@ -108,6 +108,11 @@ impl<'a> FeatureNames<'a> {
     pub fn len(&self) -> u16 {
         self.records.len()
     }
+
+    /// Checks if there are any feature names.
+    pub fn is_empty(&self) -> bool {
+        self.records.is_empty()
+    }
 }
 
 impl<'a> core::fmt::Debug for FeatureNames<'a> {

src/tables/glyf.rs

@@ -369,8 +369,8 @@ impl<'a> EndpointsIter<'a> {
                 let prev = self.endpoints.get(self.index - 1).unwrap_or(0);
                 // Malformed font can have endpoints not in increasing order,
                 // so we have to use checked_sub.
-                self.left = end.checked_sub(prev).unwrap_or(0);
-                self.left = self.left.checked_sub(1).unwrap_or(0);
+                self.left = end.saturating_sub(prev);
+                self.left = self.left.saturating_sub(1);
             }
 
             // Always advance the index, so we can check the current contour number.
@@ -508,6 +508,7 @@ impl CompositeGlyphFlags {
 // It's not defined in the spec, so we are using our own value.
 pub(crate) const MAX_COMPONENTS: u8 = 32;
 
+#[allow(clippy::comparison_chain)]
 #[inline]
 fn outline_impl(
     loca_table: loca::Table,