Needless clone, borrows, casts and lifetimes (#504)

7 files changed, 20 insertions, 14 deletions

diff --git a/library/src/layout/flow.rs b/library/src/layout/flow.rs
index da2ddba6..cd7b1f60 100644
--- a/library/src/layout/flow.rs
+++ b/library/src/layout/flow.rs
@@ -30,7 +30,7 @@ impl Layout for FlowElem {
             let mut styles = styles;
             if let Some((elem, map)) = child.to_styled() {
                 child = elem;
-                styles = outer.chain(&map);
+                styles = outer.chain(map);
             }
 
             if let Some(elem) = child.to::<VElem>() {
@@ -54,7 +54,7 @@ impl Layout for FlowElem {
                     true,
                 ));
             } else if child.can::<dyn Layout>() {
-                layouter.layout_multiple(vt, &child, styles)?;
+                layouter.layout_multiple(vt, child, styles)?;
             } else if child.is::<ColbreakElem>() {
                 if !layouter.regions.backlog.is_empty() || layouter.regions.last.is_some()
                 {
diff --git a/library/src/layout/fragment.rs b/library/src/layout/fragment.rs
index d1f6b524..3550df2a 100644
--- a/library/src/layout/fragment.rs
+++ b/library/src/layout/fragment.rs
@@ -15,6 +15,11 @@ impl Fragment {
         Self(frames)
     }
 
+    /// Return `true` if the length is 0.
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
     /// The number of frames in the fragment.
     pub fn len(&self) -> usize {
         self.0.len()
diff --git a/library/src/layout/grid.rs b/library/src/layout/grid.rs
index e0c8b684..01bf7e30 100644
--- a/library/src/layout/grid.rs
+++ b/library/src/layout/grid.rs
@@ -267,7 +267,7 @@ impl<'a, 'v> GridLayouter<'a, 'v> {
 
         // We use these regions for auto row measurement. Since at that moment,
         // columns are already sized, we can enable horizontal expansion.
-        let mut regions = regions.clone();
+        let mut regions = regions;
         regions.expand = Axes::new(true, false);
 
         Self {
diff --git a/library/src/layout/list.rs b/library/src/layout/list.rs
index 9f8d5a92..6cb1bc7e 100644
--- a/library/src/layout/list.rs
+++ b/library/src/layout/list.rs
@@ -197,7 +197,7 @@ cast_from_value! {
     ListMarker,
     v: Content => Self::Content(vec![v]),
     array: Array => {
-        if array.len() == 0 {
+        if array.is_empty() {
             Err("array must contain at least one marker")?;
         }
         Self::Content(array.into_iter().map(Value::display).collect())
diff --git a/library/src/layout/mod.rs b/library/src/layout/mod.rs
index 1e437723..e93b2e02 100644
--- a/library/src/layout/mod.rs
+++ b/library/src/layout/mod.rs
@@ -172,7 +172,7 @@ fn realize_root<'a>(
         return Ok((content.clone(), styles));
     }
 
-    let mut builder = Builder::new(vt, &scratch, true);
+    let mut builder = Builder::new(vt, scratch, true);
     builder.accept(content, styles)?;
     builder.interrupt_page(Some(styles))?;
     let (pages, shared) = builder.doc.unwrap().pages.finish();
@@ -197,7 +197,7 @@ fn realize_block<'a>(
         return Ok((content.clone(), styles));
     }
 
-    let mut builder = Builder::new(vt, &scratch, false);
+    let mut builder = Builder::new(vt, scratch, false);
     builder.accept(content, styles)?;
     builder.interrupt_par()?;
     let (children, shared) = builder.flow.0.finish();
@@ -314,7 +314,7 @@ impl<'a, 'v, 't> Builder<'a, 'v, 't> {
     ) -> SourceResult<()> {
         let stored = self.scratch.styles.alloc(styles);
         let styles = stored.chain(map);
-        self.interrupt_style(&map, None)?;
+        self.interrupt_style(map, None)?;
         self.accept(elem, styles)?;
         self.interrupt_style(map, Some(styles))?;
         Ok(())
@@ -468,9 +468,9 @@ impl<'a> FlowBuilder<'a> {
 
             let above = BlockElem::above_in(styles);
             let below = BlockElem::below_in(styles);
-            self.0.push(above.clone().pack(), styles);
+            self.0.push(above.pack(), styles);
             self.0.push(content.clone(), styles);
-            self.0.push(below.clone().pack(), styles);
+            self.0.push(below.pack(), styles);
             return true;
         }
 
diff --git a/library/src/layout/par.rs b/library/src/layout/par.rs
index dc445c86..7e43b43f 100644
--- a/library/src/layout/par.rs
+++ b/library/src/layout/par.rs
@@ -365,12 +365,13 @@ impl<'a> Item<'a> {
 }
 
 /// Maps byte offsets back to spans.
+#[derive(Default)]
 pub struct SpanMapper(Vec<(usize, Span)>);
 
 impl SpanMapper {
     /// Create a new span mapper.
     pub fn new() -> Self {
-        Self(vec![])
+        Self::default()
     }
 
     /// Push a span for a segment with the given length.
@@ -745,8 +746,8 @@ fn is_compatible(a: Script, b: Script) -> bool {
 
 /// Get a style property, but only if it is the same for all children of the
 /// paragraph.
-fn shared_get<'a, T: PartialEq>(
-    styles: StyleChain<'a>,
+fn shared_get<T: PartialEq>(
+    styles: StyleChain<'_>,
     children: &[Content],
     getter: fn(StyleChain) -> T,
 ) -> Option<T> {
@@ -754,7 +755,7 @@ fn shared_get<'a, T: PartialEq>(
     children
         .iter()
         .filter_map(|child| child.to_styled())
-        .all(|(_, local)| getter(styles.chain(&local)) == value)
+        .all(|(_, local)| getter(styles.chain(local)) == value)
         .then(|| value)
 }
 
diff --git a/library/src/layout/stack.rs b/library/src/layout/stack.rs
index c85eda2d..8146114a 100644
--- a/library/src/layout/stack.rs
+++ b/library/src/layout/stack.rs
@@ -198,7 +198,7 @@ impl<'a> StackLayouter<'a> {
         let aligns = if let Some(align) = block.to::<AlignElem>() {
             align.alignment(styles)
         } else if let Some((_, local)) = block.to_styled() {
-            AlignElem::alignment_in(styles.chain(&local))
+            AlignElem::alignment_in(styles.chain(local))
         } else {
             AlignElem::alignment_in(styles)
         }