:- module(testcondition, [go/0]). :- use_module(library(http/thread_httpd)). :- use_module(library(http/http_dispatch)). :- use_module(library(http/html_write)). go :- http_server(http_dispatch, [port(5000)]). :- http_handler(root(.) , first, [priority(100), tacos(onions)]). % :- http_handler(root(.) , second, [condition(true_one), priority(0)]). first(_R) :- reply_html_page( title(first), h1('First')). second(_R) :- reply_html_page( title(second), h1('Second')). fail_one(P) :- debug(testcondition(fail_one), 'fail_one ~w', [P]), !, fail. true_one(P) :- debug(testcondition(true_one), 'true_one ~w', [P]).