Re: table.remove bug?
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- Subject: Re: table.remove bug?
- From: "Philippe Lhoste" <PhiLho@...>
- Date: Fri, 2 Jan 2004 15:24:11 +0100 (MET)
Mark wrote:
> t = { "a", "b", "c" }
> table.remove( t, -1 )
> table.foreach( t, print )
>
> --->
>
> 1 b
> 2 c
> 0 a
>
> Doing a remove of -1 again shifts it down further.
A bug? It depends on the point of view... It may be a feature...
First, the bug is in the call. The manual says nothing about negative
positions, so the result of this call is
undefined.
Four possibilities:
- This is a feature, the behavior is on purpose. Perhaps it should be
documented...
- This is a bug, the function should raise an error on invalid input values.
- It is normal undefined behavior: as the authors often say, "garbage in,
garbage out", the C philosophy is
not to do checks on input data (or minimal ones), it is up to the caller to
verify data it provides is correct.
This allows faster routines. I believe that a scripting language should be
stricter, but why not.
- The behavior can be improved to accept negative positions, the actual
position being then "n + pos", ie.
index from the end of the table.
Regards.
--
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Philippe Lhoste (Paris -- France)
Professional programmer and amateur artist
http://jove.prohosting.com/~philho/
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