Fix range object construction in DZN parser

Fixes #18

Author: Dekker1

CHANGELOG.rst

@@ -18,6 +18,8 @@ Fixed
 ^^^^^
 - Close generated solver configuration before handing it to MiniZinc. This fixes the
   usage of generated solver configurations on Windows.
+- The DZN parser now constructs correct range objects. The parser was off by one due to
+  the exclusive upper bound in Python range objects.
 
 0.2.2_ - 2020-02-17
 -------------------

src/minizinc/dzn.py

@@ -71,7 +71,7 @@ def set(s):
         if len(s) == 1:
             return set(s[0])
         else:
-            return range(s[0], s[1])
+            return range(s[0], s[1] + 1)
 
     @staticmethod
     def string(s):

tests/test_dzn.py

@@ -51,8 +51,11 @@ def test_dzn_set():
     assert parse_dzn("x = {1.2,2.1}") == {"x": {1.2, 2.1}}
 
     # Set Ranges
-    assert parse_dzn("x = 1..1") == {"x": range(1, 1)}
-    assert parse_dzn("x = 1..3") == {"x": range(1, 3)}
+    # note: upper range limit is exclusive in Python
+    assert parse_dzn("x = 1..1") == {"x": range(1, 2)}
+    assert set(parse_dzn("x = 1..1")["x"]) == {1}
+    assert parse_dzn("x = 1..3") == {"x": range(1, 4)}
+    assert set(parse_dzn("x = 1..3")["x"]) == {1, 2, 3}
 
 
 def test_dzn_array():