let get_ready_exprs (wr: win_ref) (b: b)
: task list * b =
assert (win_valid wr b);
let task e = {
task_win = wr;
task_expr = e;
} in
let w = win_assoc_valid wr b in
let p = page_assoc_valid w.win_page b in
let (pes_ready, pes') = split_queued_exprs p.page_script_queue in
let p' = {
p with
page_script_queue = pes';
} in
let b' = page_update w.win_page p' b in
(List.map task pes_ready, b')