Re: Ann: SWI-Prolog 7.1.0

On 23/11/2013, at 6:56 AM, Alan Baljeu wrote:
> 
> I distinctly remember the awkwardness of coding expressions where 
> a term could be an atom or a list, and running into [] being both.

Well, writing stuff where "a term could be an atom or a list" was a
rather silly thing to do in the first place.

> 
>    - Quoted atoms are no longer operators.
> 
> 
> Like Haskell.  Good idea.

How is this like Haskell?
Haskell doesn't *have* atoms, and what `` quotes do in Haskell
is precisely to turn identifiers into operators.
> 
>    - Unquoted atoms may contain internal dots.  E.g., a.b is an
>      atom.
> 
> I find this confusing given V.b is emphatically not an atom.  
> What's the motivation?

Could it be the same as Erlang, where lists.iai.uni_bonn.de
is an atom?  (But lists.iai.uni-bonn.de is not; helpful tricks
that fail at unexpected moments are false friends.)

>    - functor() is valid syntax.  It produces a term that is distinct
>      from 'functor'.  The `block' operator '()' to hack this syntax
>      has been removed.
> 
> So call(plus(), 2,3,X) is now a thing?
> I used to wish for this syntax, but now I can't remember why.

Something like this used to exist in Poplog and SigmaPROLOG,
where it was an artefact of representing compound terms as
(basically) [<atom>|<array>].  As I recall, it was an unmitigated
nuisance.

>