(module
 (type $heap-object (sub (struct (field (mut i32)))))
 (type $open-procedure (func (param i32)))
 (type $closure (sub $heap-object
                     (struct (field (mut i32))
                             (field (ref $open-procedure)))))
 (type $cont-stack-type (array (mut (ref null $open-procedure))))
 (type $arg-array-type (array (mut eqref)))
 (type (func (result (ref eq))))
 (global $cont-stack-top (mut i32) (i32.const 0))
 (global $cont-stack (ref $cont-stack-type)
         (array.new_default $cont-stack-type (i32.const 128)))
 (global $arg-array (ref $arg-array-type)
         (array.new_default $arg-array-type (i32.const 32)))
 (global (mut eqref) (ref.null eq))
 (elem declare funcref (ref.func 1))
 (func $halt (param i32)
       (local (ref eq) (ref eq) (ref eq) (ref eq) (ref eq))
       (global.set 3
                   (ref.as_non_null
                    (array.get $arg-array-type
                               (global.get $arg-array)
                               (i32.const 0)))))
 (func $f1 (param i32)
       (local (ref eq) (ref eq) (ref eq) (ref eq) (ref eq))
       ;; pop arg 0
       (local.set
        1
        (ref.as_non_null
         (array.get $arg-array-type
                    (global.get $arg-array)
                    (i32.const 0))))
       ;; push arg 0
       (array.set $arg-array-type
                  (global.get $arg-array)
                  (i32.const 0)
                  (local.get 1))
       ;; pop continuation
       (return_call_ref
        $open-procedure
        (i32.const 1)
        (ref.as_non_null (array.get $cont-stack-type
                                    (global.get $cont-stack)
                                    (global.get $cont-stack-top)))
        (global.set $cont-stack-top
                    (i32.sub
                     (global.get $cont-stack-top)
                     (i32.const 1)))))
 (func $f2 (type $open-procedure) (param i32)
       (local (ref eq) (ref eq) (ref eq) (ref eq) (ref eq))
       (local.set 1
                  (struct.new $closure
                              (i32.const 0)
                              (ref.func $f1)))
       (array.set $arg-array-type
                  (global.get $arg-array)
                  (i32.const 0)
                  (local.get 1))
       (i32.const 1)
       (return_call $f1))
 (func $main (export "main") (result (ref eq))
       (local (ref eq) (ref eq) (ref eq) (ref eq) (ref eq))
       (call $f2 (i32.const 0))
       (ref.as_non_null
        (global.get 3))))