Re: segmentation fault writing cyclic term

[Paulo Moura]

Hi,

> On 4 Dec 2021, at 00:11, Paul Eggert <eggert@CS.UCLA.EDU> wrote:
> 
> This is GNU Prolog 1.5.0 running on Fedora 35 x86-64.
> 
> $ gprolog
> GNU Prolog 1.5.0 (64 bits)
> Compiled Jul 22 2021, 00:00:00 with gcc
> Copyright (C) 1999-2021 Daniel Diaz
> 
> | ?- X = X+1, write(X).
> X = X+1, write(X).
> Segmentation fault (core dumped)
> 
> 
> Shouldn't write/1 be protected against cyclic terms?

Note that support for cyclic terms is not a ISO Prolog standard requirement. In 
fact, only a few Prolog systems provide comprehensive support for cyclic terms. 
That said, better support for cyclic terms in future GNU Prolog versions would 
be most welcome.

Cheers,
Paulo


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Paulo Moura
Logtalk developer