🚀 go-pugleaf

In article 8798@iccgcc.decnet.ab.com, baechtel@iccgcc.decnet.ab.com () writes:
>
>
>	In C-Prolog 1.5, is there anyway to get the name of a variable
>in a term?
>
>	Specifically, If I write:
>
>read(Term, Vars) :-
>    read(Term),
>    functor(Term,F,A),
>    getvars(Term,A,Vars,[]).
>
>getvars(Term,0,Varlist,Varlist).
>
>getvars(Term,A,Vars,Varlist) :-
>    arg(A,Term,Arg),
>    ( var(Arg), Vars1 = [Arg | Varlist]; Vars1 = Varlist),
>    A1 is A-1,
>    getvars(Term,A1,Vars,Vars1).
>
>If I execute read(Term,Vars) and my input is: "X is Y.",
>Term = "X is Y" and Vars = [_15,_16].
>
>Is there anyway to get Vars=[X,Y]?
>I don't understand how to get the name of the Variable instead of its
>reference.

Actually, if I execute your code, I get
| ?- read(Term, Vars).
|: "X is Y".

Term = [88,32,105,115,32,89]
Vars = []  

or, if the quotes were not meant to be there,

| ?- read(Term, Vars).
|: X is Y.

Term = _6 is _7
Vars = [_6,_7] 

Most Prologs do not keep the names of variables in terms being read in.
The only exception is the top level loop, where usually a special predicate is used which returns variables together with their names as atoms. C-Prolog 1.5 has no such
predicate, the top-level answer is hard-wired. If you insist on C-Prolog, use ROK's public domain parser read.pl and rdtok.pl which gives you both the term and a list of
variable/name pairs.

--Micha

---
Micha Meier			------------------------------------------------
ECRC, Arabellastr. 17		The opinions expressed above are private
D-8000 Munich 81		and may not reflect those of my employer.
micha@ecrc.de, Tel. +49-89-92699-108, Fax  +49-89-92699-170

In article <1992Sep4.121544.13871@ecrc.de> micha@ecrc.de (Micha Meier) writes:
> In article 8798@iccgcc.decnet.ab.com, baechtel@iccgcc.decnet.ab.com () writes:
> >
> >
> >	In C-Prolog 1.5, is there anyway to get the name of a variable
> >in a term?
	.
	.
	.
	.
> [...] If you insist on
> C-Prolog, use ROK's public domain parser read.pl and rdtok.pl which
> gives you both the term and a list of variable/name pairs.

Or get c-prolog 1.6.edai:

	C Prolog version 1.6.edai
	% Restoring file /usr/local/lib/prolog/startup-1.6.edai
	yes
	| ?- read(A,B).
	|: A.
	B = [ 'A' = _0]
	A = _0
	yes

Cheers,
Vasco Pedro
--
.signature illegible