Method execute_for_iter

crates/vm/src/frame.rs:6918–6962

Advance the iterator on top of stack. Returns `true` if iteration continued (item pushed), `false` if exhausted (jumped).

(
        &mut self,
        vm: &VirtualMachine,
        target: bytecode::Label,
    )

    /// Advance the iterator on top of stack.
    /// Returns `true` if iteration continued (item pushed), `false` if exhausted (jumped).
    fn execute_for_iter(
        &mut self,
        vm: &VirtualMachine,
        target: bytecode::Label,
    ) -> Result<bool, PyBaseExceptionRef> {
        let top = self.top_value();

        // FOR_ITER_RANGE: bypass generic iterator protocol for range iterators
        if let Some(range_iter) = top.downcast_ref_if_exact::<PyRangeIterator>(vm) {
            if let Some(value) = range_iter.fast_next() {
                self.push_value(vm.ctx.new_int(value).into());
                return Ok(true);
            }
            if vm.use_tracing.get() && !vm.is_none(&self.object.trace.lock()) {
                let stop_exc = vm.new_stop_iteration(None);
                self.fire_exception_trace(&stop_exc, vm)?;
            }
            self.jump(self.for_iter_jump_target(target));
            return Ok(false);
        }

        let top_of_stack = PyIter::new(top);
        let next_obj = top_of_stack.next(vm);

        match next_obj {
            Ok(PyIterReturn::Return(value)) => {
                self.push_value(value);
                Ok(true)
            }
            Ok(PyIterReturn::StopIteration(value)) => {
                // Fire 'exception' trace event for StopIteration, matching
                // FOR_ITER's inline call to _PyEval_MonitorRaise.
                if vm.use_tracing.get() && !vm.is_none(&self.object.trace.lock()) {
                    let stop_exc = vm.new_stop_iteration(value);
                    self.fire_exception_trace(&stop_exc, vm)?;
                }
                self.jump(self.for_iter_jump_target(target));
                Ok(false)
            }
            Err(next_error) => {
                self.pop_value();
                Err(next_error)
            }
        }
    }

    /// Compute the jump target for FOR_ITER exhaustion: skip END_FOR and jump to POP_ITER.
    fn for_iter_jump_target(&self, target: bytecode::Label) -> bytecode::Label {