Re: Declarative constraints in practical terms
Date: 28 Feb 2006 20:33:42 -0800
Message-ID: <1141187622.712403.61620_at_i40g2000cwc.googlegroups.com>
ralphbecket_at_gmail.com wrote:
[...]
> That's all Prolog implementations. Despite what is often
> said, Prolog is not a declarative language; it's an imperative
> language with unification and backtracking.
[...]
Prolog is certainly not a 'pure' declarative language. However, you
have it backwards -- it's a logic programming language with a lot of
non-logical and imperative features (cut, IO, assert/retract, etc).
When you excise the non-pure part, you'll be left with a subset of FOL
(Horn clauses) and the SLD resolution.
>
> Have a look at Mercury for an example of a pragmatic,
> general purpose, high performance declarative
> programming language.
... which has the same SLD resoltion as Prolog does.
>
> -- Ralph
Received on Wed Mar 01 2006 - 05:33:42 CET