tests: Further improvements to overall system stability and other minor adjustments have been made to enhance the user experience.

src/bus.rs

@@ -51,10 +51,15 @@ pub trait Write<T> {
 #[non_exhaustive]
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum Region {
+    /// Character ROM (but writable!)
     Charset,
+    /// Program memory
     Program,
+    /// Screen buffer
     Screen,
+    /// Stack space
     Stack,
+    /// Total number of named regions
     Count,
 }
 
@@ -191,6 +196,17 @@ impl Bus {
     ///#    Ok(())
     ///# }
     /// ```
+    /// If the region doesn't exist, that's okay.
+    /// ```rust
+    ///# use chirp::prelude::*;
+    ///# fn main() -> Result<()> {
+    ///     let bus = Bus::new()
+    ///         .add_region(Program, 0..1234)
+    ///         .clear_region(Screen);
+    ///# // TODO: test if region actually clear
+    ///#    Ok(())
+    ///# }
+    /// ```
     pub fn clear_region(&mut self, name: Region) -> &mut Self {
         if let Some(region) = self.get_region_mut(name) {
             region.fill(0)

src/cpu.rs

@@ -314,6 +314,20 @@ impl CPU {
         self
     }
 
+    /// Gets a slice of breakpoints
+    /// # Examples
+    /// ```rust
+    ///# use chirp::prelude::*;
+    ///# fn main() -> Result<()> {
+    ///     let mut cpu = CPU::default();
+    ///     assert_eq!(cpu.breakpoints(), &[]);
+    ///#    Ok(())
+    ///# }
+    /// ```
+    pub fn breakpoints(&self) -> &[Adr] {
+        &self.breakpoints.as_slice()
+    }
+
     /// Unpauses the emulator for a single tick,
     /// even if cpu.flags.pause is set.
     ///

src/cpu/disassemble.rs

@@ -171,7 +171,7 @@ impl Disassemble {
                 0x65 => self.dma_load(x),
                 _ => self.unimplemented(opcode),
             },
-            _ => unimplemented!("Extracted nibble from byte, got >nibble?"),
+            _ => unreachable!("Extracted nibble from byte, got >nibble?"),
         }
     }
 }