Category : Files from Magazines
Archive   : AIFIRST.ZIP
Filename : TURBO2.LTG

Turbo PROLOG:
Database Access Benchmark



/* Test database storage and retrieval by asserting lots of facts and looking
them up. */


DATABASE

fact(INTEGER)


PREDICATES

test(INTEGER)
test2(INTEGER, INTEGER)


CLAUSES

/* Tail recursively look up a numbered fact in the database and the assert
its successor. First argument is current fact number, second argument
is limiting fact number to stop at. */

test2(X,X).
test2(X,Y) :- fact(X), Z = X + 1, assert(fact(Z)), test2(Z,Y).

/* Shorthand predicate to default the test to start with fact(1). */

test(Y) :- test2(1,Y).

fact(1). /* Seed the database with the first fact */


GOAL

/* Prompt for the limiting fact number and run the benchmark. */

nl, write(ready), nl, readint(X), test(X), write(done), nl.