From a682658a67c6b02f0817058b5c5b0ecf1377a17f Mon Sep 17 00:00:00 2001
From: Jed Barber <jjbarber@y7mail.com>
Date: Sat, 29 Mar 2014 00:59:36 +1100
Subject: Added shoot command, winning and game over conditions

---
 agent.prolog | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 59 insertions(+), 2 deletions(-)

diff --git a/agent.prolog b/agent.prolog
index ba59a43..a0c4289 100644
--- a/agent.prolog
+++ b/agent.prolog
@@ -1,5 +1,5 @@
 
-:- module(agent, [init, look/0, move/1, take/1]).
+:- module(agent, [init, look/0, move/1, take/1, shoot/1]).
 
 
 :- consult('parser.prolog').
@@ -59,7 +59,8 @@ move(Direction) :-
     retract(here(Location)),
     asserta(here(New)),
     join(['You move to the ',Direction,' .\n\n'],W),
-    write(W), !.
+    write(W), 
+    checkHazards, !.
 
 
 take(Item) :-
@@ -71,6 +72,23 @@ take(Item) :-
     write('Taken.\n\n'), !.
 
 
+shoot(Direction) :-
+    here(Location),
+    connects(Location, Target, Direction),
+    wumpusAt(Target),
+    write('You hear an unearthly scream.\n\n'),
+    retract(wumpusAt(Target)),
+    win.
+
+
+shoot(Direction) :-
+    here(Location),
+    connects(Location, Target, Direction),
+    not(wumpusAt(Target)),
+    write('Thunk. Missed.\n\n'),
+    moveWumpus.
+
+
 
 
 % letting the player know what's going on
@@ -122,6 +140,45 @@ writeExits(Location) :-
 
 
 
+% modifying things and checking the ramifications
+
+moveWumpus :-
+    wumpusAt(Old),
+    findall(X, connects(Old,X,_), PossibleNews),
+    random_member(New, PossibleNews),
+    retract(wumpusAt(Old)),
+    asserta(wumpusAt(New)),
+    checkWumpus.
+
+
+checkHazards :-
+    checkWumpus.
+
+
+checkWumpus :-
+    here(Location),
+    wumpusAt(Location),
+    lose(eaten).
+checkWumpus :- true.
+
+
+
+
+% winning, losing, and otherwise
+
+win :-
+    write('*** YOU WIN ***\n'),
+    halt(0).
+
+
+lose(eaten) :-
+    write('You have been eaten by the wumpus.\n'),
+    write('*** GAME OVER ***\n'),
+    halt(0).
+
+
+
+
 % miscellaneous clauses
 
 somethingAt(X) :- current_predicate(here/1), here(X).
-- 
cgit