TITLE

Built-ins: Merge and generalize index and rindex

VERSION

  Maintainer: Damian Conway <damian@conway.org>
  Date: 7 Aug 2000
  Mailing List: perl6-language@perl.org
  Number: 53
  Version: 10
  Status: Developing

ABSTRACT

This RFC proposes that the index and rindex functions be merged and generalized, by adding a fourth parameter to index.

DESCRIPTION

At present index only returns the index of the first occurrence of a specified substring. It is proposed that index take a fourth parameter telling it which occurrence of a specified substring to locate:

        $first = index $string, $substring, 0, 1;       # first occurrence
        $first = index $string, $substring, 0, 2;       # second occurrence
        $first = index $string, $substring, 0, 3;       # third occurrence

If omitted, this fourth parameter would default to 1, thus preversing the current behaviour.

The rindex function would be unnecessary, being replaced by:

        $last = index $string, $substring, -1, -1;      # last occurence

IMPLEMENTATION

Dammit, Jim, I'm a doctor, not an engineer!