properly compile when expressions?

src/compiler.rs

@@ -604,24 +604,24 @@ impl Compiler {
             When(clauses) => {
                 let mut jump_idxes = vec![];
                 let mut clauses = clauses.iter();
-                let stack_depth = self.stack_depth;
                 while let Some((WhenClause(cond, body), _)) = clauses.next() {
                     self.visit(cond.as_ref());
                     self.emit_op(Op::JumpIfFalse);
                     let jif_jump_idx = self.len();
                     self.emit_byte(0xff);
+                    self.stack_depth -= 1;
                     self.visit(body);
                     self.emit_op(Op::Jump);
                     jump_idxes.push(self.len());
                     self.emit_byte(0xff);
                     self.chunk.bytecode[jif_jump_idx] = self.len() as u8 - jif_jump_idx as u8 - 1;
-                    self.stack_depth = stack_depth;
+                    self.stack_depth -= 1;
                 }
-                self.stack_depth += 1;
                 self.emit_op(Op::PanicNoWhen);
                 for idx in jump_idxes {
-                    self.chunk.bytecode[idx] = self.len() as u8 - idx as u8 + 1;
+                    self.chunk.bytecode[idx] = self.len() as u8 - idx as u8 - 1;
                 }
+                self.stack_depth += 1;
             }
             WhenClause(..) => unreachable!(),
             Match(scrutinee, clauses) => {

src/main.rs

@@ -74,15 +74,7 @@ pub fn run(src: &'static str) {
 pub fn main() {
     env::set_var("RUST_BACKTRACE", "1");
     let src = "
-let x = when {
+    
-    false -> :no
-    nil -> {
-        let x = :no
-        x
-    }
-    :else -> :yes
-}
-x
     ";
     run(src);
 }