Break out step()

src/vm.rs

@@ -12,6 +12,7 @@ pub enum UxnError {
     StackError(StackError),
     MemoryError(MemoryError),
     ExecutionLimit(u16),
+    Break,
     ArithmeticOverflow,
     ArithmeticUnderflow,
     DivisionByZero,
@@ -111,22 +112,6 @@ impl Uxn {
 
     // Run one clock cycle (instruction)
     pub fn step(&mut self) -> Result<(), UxnError> {
-        Ok(())
-    }
-
-    pub fn run(&mut self, limit: u16) -> Result<(), UxnError> {
-        let mut executed = 0;
-        'run: loop {
-            if executed == limit {
-                return Err(UxnError::ExecutionLimit(executed));
-            }
-
-            if self.is_halted() {
-                break;
-            }
-
-            executed += 1;
-
         match self.lda1(self.pc) {
             Err(e) => return Err(UxnError::MemoryError(e)),
             Ok(opcode) => {
@@ -189,7 +174,7 @@ impl Uxn {
                 match (kflag, rflag, sflag, icode) {
                     (0, 0, 0, 0x00) => {
                         // BRK
-                            break 'run;
+                        return Err(UxnError::Break);
                     }
                     (_, _, _, 0x00) => {
                         // LIT
@@ -408,6 +393,26 @@ impl Uxn {
                 }
             }
         }
+        Ok(())
+    }
+
+    pub fn run(&mut self, limit: u16) -> Result<(), UxnError> {
+        let mut executed = 0;
+        loop {
+            if executed == limit {
+                return Err(UxnError::ExecutionLimit(executed));
+            }
+
+            if self.is_halted() {
+                break;
+            }
+
+            executed += 1;
+
+            match self.step() {
+                Err(e) => return Err(e),
+                Ok(()) => continue,
+            };
         }
         Ok(())
     }