(arg) - JavaScript

argument and parameter positions

(arg pos? val?)

Where:

1. pos: position in the list (1-based) *
2. val: value at that position *

Examples

Find zero-delay timers that can starve the main thread.

(call setTimeout (arg 2 (num 0)))

Selects in lines { 1 } but not in { 2, 3 }:

setTimeout(tick, 0)
setTimeout(tick, 250)
setInterval(tick, 0)

---

Identify request handlers when migrating server frameworks.

(fun _ (:and (arg 1 (id req)) (arg 2 (id res))))

Selects in lines { 1, 2 } but not in { 3 }:

function handle(req, res) {}
const handleArrow = (req, res) => {}
function reversed(res, req) {}

---

Find one-time event listeners that are safe to remove manually.

(call (mem addEventListener) (arg 3 (obj (prop once))))

Selects in lines { 1 } but not in { 2, 3 }:

button.addEventListener("click", onClick, { once: true })
window.addEventListener("scroll", onScroll, { passive: true })
document.addEventListener("keydown", onKey)

---

Arguments

pos

1. Number

Does NOT support: Composition — Free-form Selection — Refinement — Replacement

val

1. Identifier: shorthand for (id)
   
2. String: shorthand for (str)
   
3. (:into)
4. (:nearest)
5. (:and)
6. (:or)
7. (:not)
8. (:text)
9. (:kind)
10. (:replace)
11. (:replace-in)
12. (:capture)
13. (:ref)
14. (arr)
15. (attr)
16. (bool)
17. (call)
18. (child)
19. (comp)
20. (export)
21. (fun)
22. (id)
23. (id+)
24. (import)
25. (jsx)
26. (mem)
27. (null)
28. (num)
29. (obj)
30. (of)
31. (prop)
32. (regex)
33. (regex+)
34. (str)
35. (str*)
36. (str+)
37. (tpl)
38. (tpl*)
39. (var)