Subject: Re: [SWIPL] Type error vs. silent failure

From: Paulo Moura <[email-masked]>
Date: Fri, 26 Oct 2001 14:34:58 +0100

On Sexta, Outubro 26, 2001, at 12:01 , Jan Wielemaker wrote:

> Gernot,
>
>> [ Sorry, must have been discussed in the past, but couldn't find 
>> anything ]
>
> Not on this list, but in general, I assume it must be.
>
>> Is there any rational behind
>>    nth1(a, [a,b,c], X).
>> failing silently and
>>    length([a,b,c], a).
>> giving a type error?
>
> Not really, apart from the fact that length is part of the ISO standard
> and the standard prescribes the tests to be made and the exceptions they
> should raise, while nth1/3 isn't.

Hum? I'm almost certain that length/2 is NOT in the ISO standard.

Paulo

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