gistfile1.md

Before

1. Let O be the result of calling ToObject passing the this value as the argument.
2. ReturnIfAbrupt(O).
3. Let len be ToLength(Get(O, "length")).
4. ReturnIfAbrupt(len).
5. If len is 0, return false.
6. Let n be ToInteger(fromIndex). (If fromIndex is undefined, this step produces the value 0.)
7. ReturnIfAbrupt(n).
8. If n ≥ 0, then
9. Let k be n.
10. Else n < 0,
11. Let k be len + n.
12. If k < 0, then let k be 0.
13. Repeat, while k < len
14. Let elementK be the result of Get(O, ToString(k)).
15. ReturnIfAbrupt(elementK).
16. If SameValueZero(searchElement, elementK) is true, return true.
17. Increase k by 1.
18. Return *false

Proposed?

1. let O = @Try(ToObject(this))
2. let len = @Try(ToLength(Get(O, "length")))
3. if len is 0, return false
4. let n = @Try(ToInteger(fromIndex)) (If fromIndex is undefined, this step produces the value 0.)
5. if n ≥ 0, then
6. let k be n
7. else n < 0,
8. let k = len + n
9. if k < 0, then let k = 0
10. while k < len
11. let elementK = @Try(Get(O, ToString(k)))
12. if SameValueZero(searchElement, elementK) is true, return true.
13. increment k
14. Return false

With ? Postfix

1. let O = ToObject(this)?
2. let len = ToLength(Get(O, "length"))?
3. if len is 0, return false.
4. let n = ToInteger(fromIndex)? (If fromIndex is undefined, this step produces the value 0.)
5. if n ≥ 0, then
6. let k be n
7. else n < 0,
8. let k = len + n
9. if k < 0, then let k = 0
10. while k < len
11. let elementK = Get(O, ToString(k))?
12. if SameValueZero(searchElement, elementK) is true, return true.
13. increment k
14. Return false