Parser `parse-toggle-cmd`: after the leading class ref, collect any
additional class refs and treat `toggle .foo .bar` as `toggle-between`
(pair-only). Recognise a `until EVENT [from SOURCE]` modifier and emit
a new `toggle-class-until` AST node. Compiler handles the new node by
emitting `(begin (hs-toggle-class! tgt cls) (hs-wait-for src ev)
(hs-toggle-class! tgt cls))` which uses the existing event-waiter
machinery to flip the class back when the specified event fires.
Remaining toggle test (`can toggle for a fixed amount of time`)
depends on the mock's sync io-sleep resuming immediately — the click
handler toggles on/off synchronously, so the pre-timeout assertion
can never see the `.foo` class present. Needs an async scheduler in
the mock to handle.
Suite hs-upstream-toggle: 22/25 → 24/25. Smoke 0-195: 162/195
unchanged.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
giles
bd821c0445