1 files changed, 37 insertions, 24 deletions
diff --git a/bytecode/src/bytecode.rs b/bytecode/src/bytecode.rs
index 73c8f53..8d24840 100644
--- a/bytecode/src/bytecode.rs
+++ b/bytecode/src/bytecode.rs
@@ -336,6 +336,36 @@ impl Interpreter {
         self.set_arg(dest, Value::from_bool(self.read_arg(x) == self.read_arg(y)));
     }
 
+    fn eval_op(&mut self, op: Op, ip: &mut usize) -> Result<Option<u8>, String> {
+        match op {
+            Op::Add(dest, x, y) => self.add(dest, x, y)?,
+            Op::Sub(dest, x, y) => self.sub(dest, x, y)?,
+            Op::Mul(dest, x, y) => self.mul(dest, x, y)?,
+            Op::Div(dest, x, y) => self.div(dest, x, y)?,
+            Op::Mod(dest, x, y) => self.fn_mod(dest, x, y)?,
+            Op::Less(dest, x, y) => self.less(dest, x, y)?,
+            Op::Alloc(dest, size) => self.alloc(dest, size)?,
+            Op::AllocBytevector(dest, size) => self.alloc_bytevector(dest, size)?,
+            Op::Peek(dest, ptr, offset) => self.peek(dest, ptr, offset)?,
+            Op::Poke(word, ptr, offset) => self.poke(word, ptr, offset)?,
+            Op::PeekByte(dest, ptr, offset) => self.peek_byte(dest, ptr, offset)?,
+            Op::PokeByte(word, ptr, offset) => self.poke_byte(word, ptr, offset)?,
+            Op::Cons(dest, x, y) => self.cons(dest, x, y)?,
+            Op::Len(dest, l) => self.len(dest, l)?,
+            Op::AssertSingleton(dest, l) => self.assert_singleton(dest, l)?,
+            Op::Mov(dest, src) => self.mov(dest, src),
+            Op::Jmp(addr) => self.jmp(ip, addr)?,
+            Op::JmpIf(cond, addr) => self.jmp_if(ip, cond, addr)?,
+            Op::Exit(code) => {
+                let n = self.read_arg(code).to_int()?;
+                return Ok(Some((n & 0xff) as u8));
+            }
+            Op::TypeOf(dest, arg) => self.type_of(dest, arg)?,
+            Op::Equal(dest, x, y) => self.equal(dest, x, y),
+        }
+        return Ok(None);
+    }
+
     fn eval(&mut self, prog: &[Op]) -> Result<u8, String> {
         let mut ip = 0;
         loop {
@@ -344,31 +374,14 @@ impl Interpreter {
             }
             let op = prog[ip];
             ip += 1;
-            match op {
-                Op::Add(dest, x, y) => self.add(dest, x, y)?,
-                Op::Sub(dest, x, y) => self.sub(dest, x, y)?,
-                Op::Mul(dest, x, y) => self.mul(dest, x, y)?,
-                Op::Div(dest, x, y) => self.div(dest, x, y)?,
-                Op::Mod(dest, x, y) => self.fn_mod(dest, x, y)?,
-                Op::Less(dest, x, y) => self.less(dest, x, y)?,
-                Op::Alloc(dest, size) => self.alloc(dest, size)?,
-                Op::AllocBytevector(dest, size) => self.alloc_bytevector(dest, size)?,
-                Op::Peek(dest, ptr, offset) => self.peek(dest, ptr, offset)?,
-                Op::Poke(word, ptr, offset) => self.poke(word, ptr, offset)?,
-                Op::PeekByte(dest, ptr, offset) => self.peek_byte(dest, ptr, offset)?,
-                Op::PokeByte(word, ptr, offset) => self.poke_byte(word, ptr, offset)?,
-                Op::Cons(dest, x, y) => self.cons(dest, x, y)?,
-                Op::Len(dest, l) => self.len(dest, l)?,
-                Op::AssertSingleton(dest, l) => self.assert_singleton(dest, l)?,
-                Op::Mov(dest, src) => self.mov(dest, src),
-                Op::Jmp(addr) => self.jmp(&mut ip, addr)?,
-                Op::JmpIf(cond, addr) => self.jmp_if(&mut ip, cond, addr)?,
-                Op::Exit(code) => {
-                    let n = self.read_arg(code).to_int()?;
-                    return Ok((n & 0xff) as u8);
+            match self.eval_op(op, &mut ip) {
+                Ok(None) => (),
+                Ok(Some(code)) => {
+                    return Ok(code);
+                }
+                Err(err) => {
+                    return Err(format!("{}: failed ({:?}): {}", ip, op, err));
                 }
-                Op::TypeOf(dest, arg) => self.type_of(dest, arg)?,
-                Op::Equal(dest, x, y) => self.equal(dest, x, y),
             }
         }
     }