[erlang-questions] index for lists and tuples?

Steve Kirsch <>
Sat Apr 18 18:18:26 CEST 2009


Thanks for the reference. I agree with the poster who suggested
lists:pos.

There are times you really want this (such as in my case where other
solutions would be more clunky) and the suggested lists:pos would be a
natural way to do this. This seems like a surprising omission from an
otherwise pretty complete set of functions.

-----Original Message-----
From: Colm Dougan [mailto:] 

On Fri, Apr 17, 2009 at 6:16 AM, Steve Kirsch <>
wrote:
> I am looking for an index function for lists and tuples that returns 
> the index of the first element that matches a query term.
>
> For example:
>
> index({a, b, c}, b) would return 2
>
> index([a, b, c], c) would return 3

Steve, there is no such function in the general case but the subject was
discussed in a recent thread :

 
http://www.erlang.org/pipermail/erlang-questions/2008-November/040189.ht
ml

Colm



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