Implement Clone for Buffer and use Arc::make_mut

src/buffer.rs

@@ -237,6 +237,21 @@ pub struct Buffer {
     scratch: ShapeBuffer,
 }
 
+impl Clone for Buffer {
+    fn clone(&self) -> Self {
+        Self {
+            lines: self.lines.clone(),
+            metrics: self.metrics,
+            width: self.width,
+            height: self.height,
+            scroll: self.scroll,
+            redraw: self.redraw,
+            wrap: self.wrap,
+            scratch: ShapeBuffer::default(),
+        }
+    }
+}
+
 impl Buffer {
     /// Create an empty [`Buffer`] with the provided [`Metrics`].
     /// This is useful for initializing a [`Buffer`] without a [`FontSystem`].

src/buffer_line.rs

@@ -4,7 +4,7 @@ use alloc::{string::String, vec::Vec};
 use crate::{Align, AttrsList, FontSystem, LayoutLine, ShapeBuffer, ShapeLine, Shaping, Wrap};
 
 /// A line (or paragraph) of text that is shaped and laid out
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct BufferLine {
     //TODO: make this not pub(crate)
     text: String,

src/edit/mod.rs

@@ -176,11 +176,7 @@ pub trait Edit<'buffer> {
         match self.buffer_ref_mut() {
             BufferRef::Owned(buffer) => f(buffer),
             BufferRef::Borrowed(buffer) => f(buffer),
-            BufferRef::Arc(arc) => match Arc::get_mut(arc) {
-                Some(buffer) => f(buffer),
-                //TODO: use make_mut?
-                None => panic!("BufferRef::Arc cannot be accessed mutibly"),
-            },
+            BufferRef::Arc(buffer) => f(Arc::make_mut(buffer)),
         }
     }
 

src/shape.rs

@@ -379,7 +379,7 @@ fn shape_skip(
 }
 
 /// A shaped glyph
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct ShapeGlyph {
     pub start: usize,
     pub end: usize,
@@ -423,7 +423,7 @@ impl ShapeGlyph {
 }
 
 /// A shaped word (for word wrapping)
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct ShapeWord {
     pub blank: bool,
     pub glyphs: Vec<ShapeGlyph>,
@@ -527,7 +527,7 @@ impl ShapeWord {
 }
 
 /// A shaped span (for bidirectional processing)
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct ShapeSpan {
     pub level: unicode_bidi::Level,
     pub words: Vec<ShapeWord>,
@@ -638,7 +638,7 @@ impl ShapeSpan {
 }
 
 /// A shaped line (or paragraph)
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct ShapeLine {
     pub rtl: bool,
     pub spans: Vec<ShapeSpan>,