From: Mark Thom <markjordanthom@gmail.com>
Date: Wed, 24 Apr 2019 02:27:47 +0000 (-0600)
Subject: address issues #111 and #108
X-Git-Tag: v0.8.110~88
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=01e57f83ee63cdb430cfc4dacdda474688462f82;p=scryer-prolog.git

address issues #111 and #108
---

diff --git a/src/prolog/lib/between.pl b/src/prolog/lib/between.pl
index 6def3ce7..38d058c8 100644
--- a/src/prolog/lib/between.pl
+++ b/src/prolog/lib/between.pl
@@ -8,6 +8,7 @@
 between(Lower, Upper, X) :-
     must_be(integer, Lower),
     must_be(integer, Upper),
+    can_be(integer, X).
     between_(Lower, Upper, X).
 
 between_(Lower, Upper, Lower) :-
@@ -15,7 +16,7 @@ between_(Lower, Upper, Lower) :-
 between_(Lower1, Upper, X) :-
     Lower1 < Upper,
     Lower2 is Lower1 + 1,
-    between(Lower2, Upper, X).
+    between_(Lower2, Upper, X).
 
 enumerate_nats(I, I).
 enumerate_nats(I0, N) :-
diff --git a/src/prolog/lib/lists.pl b/src/prolog/lib/lists.pl
index b058b2c5..0e4ae7a3 100644
--- a/src/prolog/lib/lists.pl
+++ b/src/prolog/lib/lists.pl
@@ -42,7 +42,7 @@ append([X|L], R, [X|S]) :- append(L, R, S).
 memberchk(X, Xs) :- member(X, Xs), !.
 
 reverse(Xs, Ys) :-
-    (  var(Ys) -> reverse(Xs, Ys, [], Xs)
+    (  nonvar(Xs) -> reverse(Xs, Ys, [], Xs)
     ;  reverse(Ys, Xs, [], Ys)
     ).