From Newsgroup: comp.lang.prolog

Hi,

Maybe its not clear to the Prolog community
what Problems string lists can create, and what
potential solutions exists. This complete

unawareness, leads to funny results:

?- test(X), X = [A|_].
X: abc, A: _13 (3.6ms)

?- test(X), X == [a,b,c].
No results

So what is going on? Any clues?

Basically entering the rabit hole that Atom
type CharList requires all code places that use
CONS Cells to have scrutinized and possibly changed .

A rabit hole that lets Scryer Prolog already
suffer as Markus Triska has expressed.

Bye
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: comp.lang.prolog

Hi,

Some Prolog Veterans might know the Solution:
ADTs . At least I have have myself already
experimented with string lists 30 years ago,

and the quickest prototype used Abstract
Data Types (ADTs). But usually a Prolog system
cannot apply them so easily, since the CONS Cells

are usually not ADTs itself already. Also these
ADTs would not necessarely use heap marking,
the more easier solution is to let them use a

garbage collecting heap, something that Heap/Stack
Prolog systems might have, but I am not sure
whether WebPL has such a heap.

Bye

Mild Shock schrieb:

Hi,

Maybe its not clear to the Prolog community
what Problems string lists can create, and what
potential solutions exists. This complete

unawareness, leads to funny results:

?- test(X), X = [A|_].
X: abc, A: _13 (3.6ms)

?- test(X), X == [a,b,c].
No results

So what is going on? Any clues?

Basically entering the rabit hole that Atom
type CharList requires all code places that use
CONS Cells to have scrutinized and possibly changed .

A rabit hole that lets Scryer Prolog already
suffer as Markus Triska has expressed.

Bye

--- Synchronet 3.21a-Linux NewsLink 1.2