From jan@swi.psy.uva.nl Sun Jan 27 17:08:58 2002
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Date: Sun, 27 Jan 2002 17:08:57 +0100
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From: Jan Wielemaker <jan@swi.psy.uva.nl>
Subject: Re: [SWIPL] string/1
To: "Michael A. Covington" <mc@arches.uga.edu>, <prolog@swi.psy.uva.nl>,
   prolog-request@swi.psy.uva.nl
Phone: +31 - 20 - 525 6121

Maybe this should be in the FAQ.  Most of the info is in

http://www.swi.psy.uva.nl/projects/SWI-Prolog/Manual/strings.html

Briefly, using default settings strings cannot be read.  You can modify
the prolog flag double_quotes:

?- set_prolog_flag(double_quotes, string).

?- string("foobar").

Yes

Think carefully before using strings.  See comments in the manual.

	--- Jan

> Under what conditions does string/1 succeed?  Not any of these... !
> 
> 
> ?- string("abc").
> No
> 
> ?- string('abc').
> No
> 
> ?- string([a,b,c]).
> No
> 
> ?- string(`abc`).
> ERROR: Syntax error: Operator expected
> ERROR: string(`
> ERROR: ** here **
> ERROR: abc`) . 

