Created the library random and moved some predicates from iso_ext

src/prolog/lib/iso_ext.pl

@@ -4,10 +4,10 @@
 %% ?- use_module(library(iso_ext)).
 
 :- module(iso_ext, [bb_b_put/2, bb_get/2, bb_put/2, call_cleanup/2,
-		            call_with_inference_limit/3, forall/2, maybe/0,
+                    call_with_inference_limit/3, forall/2,
                     partial_string/1, partial_string/3,
-		            partial_string_tail/2, set_random/1,
-		            setup_call_cleanup/3, variant/2]).
+                    partial_string_tail/2, setup_call_cleanup/3,
+                    variant/2]).
 
 forall(Generate, Test) :-
     \+ (Generate, \+ Test).
@@ -144,21 +144,6 @@ call_with_inference_limit(_, _, R, Bb, B) :-
 
 variant(X, Y) :- '$variant'(X, Y).
 
-% succeeds with probability 0.5.
-maybe :- '$maybe'.
-
-set_random(Seed) :-
-    (  nonvar(Seed) ->
-       (  Seed = seed(S) ->
-	  (  var(S) -> throw(error(instantiation_error, set_random/1))
-	  ;  integer(S) -> '$set_seed'(S)
-	  ;  throw(error(type_error(integer(S), set_random/1)))
-	  )
-       )
-    ;  throw(error(instantiation_error, set_random/1))
-    ).
-
-
 partial_string(String, L, L0) :-
     (  String == [] ->
        L = L0

src/prolog/lib/random.pl

@@ -0,0 +1,16 @@
+:- module(random, [maybe/0, set_random/1]).
+
+% succeeds with probability 0.5.
+maybe :- '$maybe'.
+
+set_random(Seed) :-
+    (   nonvar(Seed) ->
+        (  Seed = seed(S) ->
+        (  var(S) -> throw(error(instantiation_error, set_random/1))
+        ;  integer(S) -> '$set_seed'(S)
+        ;  throw(error(type_error(integer(S), set_random/1)))
+        )
+        )
+    ;   throw(error(instantiation_error, set_random/1))
+    ).
+