Sent: Friday, July 21, 2000 5:06 PM Subject: RE: Modifying consulted rules "no permission to modify static procedures" is ussuly due to a syntactical misplacement of a comma or semicollon in code one missing period or one comma can make the prolog engine think you are trying to add your own version of ','(_,_). ------_=_NextPart_001_01BFF3FC.761132D0 Content-Type: text/html; charset="ISO-8859-1"

Jason,

try this out and see if it is what you want...

in "consultTest.txt" put these 4 lines:

:-dynamic(test/1). % this will make sure it doesnt compile the test/1 predicates in this file

test(1).

test(original).

test(3).

open the standalone prolog shell..

?- consult('consultTest.txt') . % or ['consultTest.txt'] would have done the same.

?- listing(test).

test(1).

test(original).

test(3).

?- asserta(test(a)),assertz(test(z)).

?- retract(test(1)).

?- listing(test).

test(a).

test(original).

test(3).

test(z).

?- consult('consultTest.txt'), listing(test).

test(1).

test(original).

test(3).

?- assert(test(z)),listing(test).

test(1).

test(original).

test(3).

test(z).

% now in the top of "consultTest.txt" put the line

:-multifile(test/1).

?- consult('consultTest.txt'), listing(test).

test(z).

test(1).

test(original).

test(3).

The problem you had ran into is when the file was consulted it also compiled test/1. as static (static is default).

Since Prolog is a programming language as well as a smart database..

When I have a list of facts this is how i import them...

load_datafile(DataFile) :-

see(DataFile),

repeat,

read(Datum),assert(Datum),

Datum=end_of_file,seen,retract(Datum).

% the last 'retract' takes out the end_of_file :)

Jan is there implemented a 'Default consulting mode' flag somewhere that can be defaulted to dynamic and/or multifile?

-----Original Message-----
From: Jason Che-han Yip [mailto:yip@ee.ualberta.ca]
Sent: Saturday, July 22, 2000 9:14 AM
To: Douglas Miles (Volt Computer)
Subject: Re: Modifying consulted rules

Here's my test running SWI-Prolog stand-alone:

I have a file "consultTest.txt" with the fact test(original).

I consult this file. listing shows that test(original) is now in the database.

I try assert(test(new)) and I get ERROR: No permission to modify static_procedure 'test_1'

So I try assert(newTest(old)), check listing, it's there.

Try assert(newTest(new)). Checking listing shows both newTest(old) and newTest(new)

----

So I figured that consulted facts/rules were un-modifiable but I didn't think that was supposed to be the case?

----- Original Message -----

From: Douglas Miles (Volt Computer)

To: 'Jason Che-han Yip' ; prolog@swi.psy.uva.nl

Sent: Friday, July 21, 2000 5:06 PM

Subject: RE: Modifying consulted rules

"no permission to modify static procedures"

is ussuly due to a syntactical misplacement of a comma or semicollon in code

one missing period or one comma can make the prolog engine think you are trying to add your own version of ','(_,_).

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