I agree that the parameter name `n` is not ideal. For example, in
`regexp_replace` it's easy to misinterpret it as "make up to n
replacements". This has not been a problem when `n` only lives in the
documentation which explains exactly what it does, but that context is
not readily available in code expressing `n => 3`.

Another possibility is `index`, which is relatively short and not a
reserved keyword ^1. `position` is not as precise but would avoid the
conceptual overloading of ordinary indices.

I'm not a fan of "index" since that leaves the question of whether it's 0 or 1 based. "Position" is a bit better, but I think Jian's suggestion of "occurance" is best.

--
Jim Nasby, Data Architect, Austin TX