> How do I code to generate symbols at runtime? "define-symbol" seems to work
> only at compile time.
Oh, I was able to do it as follows:
[ "a-symbol" "factor-logica" create-word define-symbol ] with-compilation-unit
--
KUSUMOTO Norio
> 2019/09/17 19:40、KUSUMOTO Norio <kusum...@na.rim.or.jp>のメール:
>
> Hello all,
>
>
> How do I code to generate symbols at runtime? "define-symbol" seems to work
> only at compile time.
>
> I'm writing an embedded language that runs on Factor with the capabilities of
> a subset of Prolog. To achieve the anonymous variable functionality, I want to
> generate as many symbols as needed at runtime.
>
> In the following code, the Prolog anonymous variables '_' are equivalent
> to explicitly generated N1 to N11 logical variables. I want to automate
> that operation.
>
>
> USING: actor-logica factor-logica.built-in lists ;
>
> ! Do the same as this Prolog program
> !
> ! neighbor(L,R,[L,R|_]).
> ! neighbor(L,R,[_|Xs]) :- neighbor(L,R,Xs).
> !
> ! zebra(X) :- Street = [H1,H2,H3],
> ! member(house(red,english,_), Street),
> ! member(house(_,spanish,dog), Street),
> ! neighbor(house(_,_,cat), house(_,japanese,_), Street),
> ! neighbor(house(_,_,cat), house(blue,_,_), Street),
> ! member(house(_,X,zebra),Street).
>
> LOGIC-PREDS: neighboro zebrao ;
> LOGIC-VARS: L R X Xs H1 H2 H3 Street ;
> LOGIC-VARS: N1 N2 N3 N4 N5 N6 N7 N8 N9 N10 N11 ;
> SYMBOLS: red blue ;
> SYMBOLS: english spanish japanese ;
> SYMBOLS: dog cat zebra ;
> TUPLE: house color nationality pet ;
>
> { neighboro L R [ L R N1 cons cons ] } semper
> { neighboro L R [ N1 Xs cons ] } { neighboro L R Xs } si
>
> { zebrao X } {
> { (=) Street [ { H1 H2 H3 } >list ] }
> { membero [ T{ house f red english N1 } ] Street }
> { membero [ T{ house f N2 spanish dog } ] Street }
> { neighboro [ T{ house f N3 N4 cat } ] [ T{ house f N5 japanese N6 } ]
> Street }
> { neighboro [ T{ house f N7 N8 cat } ] [ T{ house f blue N9 N10 } ] Street
> }
> { membero [ T{ house f N11 X zebra } ] Street }
> } si
>
>
> Loading resource:work/factor-logica/factor-logica.factor
> Loading resource:work/factor-logica/built-in/built-in.factor
> IN: scratchpad { zebrao X } query .
> { H{ { X japanese } } H{ { X japanese } } }
>
>
> --
> KUSUMOTO Norio
>
>
>
>
>
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