2008-02-17 Douglas S. Blank <dblank@cs.brynmawr.edu>

* src/gen/lib/date.py (Date.__sub__): fixed some date math (#1649)
	* src/gen/lib/test/date_test.py: added some unit tests for date math



svn: r10043

ChangeLog

@@ -1,3 +1,7 @@
+2008-02-17  Douglas S. Blank  <dblank@cs.brynmawr.edu>
+	* src/gen/lib/date.py (Date.__sub__): fixed some date math (#1649)
+	* src/gen/lib/test/date_test.py: added some unit tests for date math
+
 2008-02-15 Gary Burton <gary.burton@zen.co.uk>
 	* src/DataViews/RelationView.py:
 	* src/Editors/_EditFamily.py: prevent right mouse button causing crash.

src/gen/lib/date.py

@@ -246,13 +246,20 @@ class Date:
         """
         Date artithmetic: Date() - years, Date - (y,m,d), or Date() - Date()
         """
-        if type(other) == int:
+        if type(other) == int:                # Date - value -> Date
             return self.copy_offset_ymd(-other)
-        elif type(other) == type(self): # date
+        elif type(other) in [tuple, list]:    # Date - (y, m, d) -> Date
+            return self.copy_offset_ymd(*map(lambda x: -x, other))
+        elif type(other) == type(self):       # Date1 - Date2 -> tuple
+            # We should make sure that Date2 + tuple -> Date1 and
+            #                          Date1 - tuple -> Date2
             d1 = map(lambda i: i or 1, self.get_ymd())
             d2 = map(lambda i: i or 1, other.get_ymd())
+            date1 = self
+            date2 = other
             if d1 < d2:
                 d1, d2 = d2, d1
+                date1, date2 = date2, date1
             # d1 - d2 (1998, 12, 32) - (1982, 12, 15) = 
             # days:
             if d2[2] > d1[2]:
@@ -275,12 +282,33 @@ class Date:
             if months > 12:
                 years += months / 12
                 months = months % 12
-            return (years, months, days)
+            # estimate: (years, months, days)
-        elif type(other) in [tuple, list]:
+            # Check transitivity:
-            return self.copy_offset_ymd(*map(lambda x: -x, other))
+            eDate = date1 - (years, months, days)
+            if eDate < date2: # too small
+                diff = 0
+                while eDate < date2 and diff < 60:
+                    diff += 1
+                    eDate = eDate + (0, 0, diff)
+                if diff == 60:
+                    return (0, 0, 0)
+                return (years, months, days - diff)
+            elif eDate > date2:
+                diff = 0
+                while eDate > date2 and diff > -60:
+                    diff -= 1
+                    eDate = eDate - (0, 0, abs(diff))
+                if diff == -60:
+                    return (0, 0, 0)
+                return (years, months, days + diff)
+            else:
+                return (years, months, days)
         else:
             raise AttributeError, "unknown date sub type: %s " % type(other)
 
+    def __eq__(self, other):
+        return self.sortval == other.sortval
+
     def __lt__(self, other):
         return self.sortval < other.sortval
 
@@ -629,12 +657,18 @@ class Date:
         if dv[Date._POS_MON]:
             dv[Date._POS_MON] += month
         elif month:
-            dv[Date._POS_MON] = month
+            if month < 0:
+                dv[Date._POS_MON] = 1 + month
+            else:
+                dv[Date._POS_MON] = month
         # Fix if month out of bounds:
         if month != 0: # only check if changed
-            if dv[Date._POS_MON] <= 0: # subtraction
+            if dv[Date._POS_MON] == 0: # subtraction
-                dv[Date._POS_YR] -= int(-dv[Date._POS_MON] / 12)
+                dv[Date._POS_MON] = 12
-                dv[Date._POS_MON] = 13 - dv[Date._POS_MON] % 12
+                dv[Date._POS_YR] -= 1
+            elif dv[Date._POS_MON] < 0: # subtraction
+                dv[Date._POS_YR] -= int((-dv[Date._POS_MON]) / 12) + 1
+                dv[Date._POS_MON] = (dv[Date._POS_MON] % 12)
             elif dv[Date._POS_MON] > 12 or dv[Date._POS_MON] < 1:
                 dv[Date._POS_YR] += int(dv[Date._POS_MON] / 12)
                 dv[Date._POS_MON] = dv[Date._POS_MON] % 12

src/gen/lib/test/date_test.py

@@ -135,5 +135,65 @@ def suite():
         count += 1
     return suite
 
+def assert_func(exp1, exp2):
+    Date = date.Date
+    e1 = eval(exp1)
+    e2 = eval(exp2)
+    assert e1 == e2, "%s should be %s but was %s" % (exp1, e2, e1)
+
+class Assert(unittest.TestCase):
+    def __init__(self, method_name, part, exp1, exp2):
+        self.__dict__[method_name + ("-%d" % part)] = \
+            lambda: assert_func(exp1, exp2)
+        unittest.TestCase.__init__(self, method_name + ("-%d" % part))
+
+def suite2():
+    """ interface to automated test runner test/regrtest.py """
+    Config.set(Config.DATE_BEFORE_RANGE, 9999)
+    Config.set(Config.DATE_AFTER_RANGE, 9999)
+    Config.set(Config.DATE_ABOUT_RANGE, 10)
+    tests = [
+        # Date +/- int/tuple -> Date
+        ("Date(2008, 1, 1) - 1", "Date(2007, 1, 1)"),
+        ("Date(2008, 1, 1) + 1", "Date(2009, 1, 1)"),
+        ("Date(2008, 1, 1) - (0,0,1)", "Date(2007, 12, 31)"),
+        ("Date(2008, 1, 1) - (0,0,2)", "Date(2007, 12, 30)"),
+        ("Date(2008) - (0,0,1)", "Date(2007, 12, 31)"),
+        ("Date(2008) - 1", "Date(2007, 1, 1)"),
+        ("Date(2008, 12, 31) + (0, 0, 1)", "Date(2009, 1, 1)"),
+        ("Date(2000,1,1) - (0,11,0)", "Date(1999,02,01)"),
+        ("Date(2000,1,1) - (0,1,0)", "Date(1999, 12, 1)"),
+        ("Date(2008, 1, 1) + (0, 0, 32)", "Date(2008, 02, 02)"),
+        ("Date(2008, 2, 1) + (0, 0, 32)", "Date(2008, 03, 04)"),
+        ("Date(2000) - (0, 1, 0)", "Date(1999, 12, 1)"),
+        ("Date(2000) + (0, 1, 0)", "Date(2000, 1, 0)"), # Ok?
+        ("Date(2000, 1, 1) - (0, 1, 0)", "Date(1999, 12, 1)"),
+        ("Date(2000, 1, 1) - 1", "Date(1999, 1, 1)"),
+        ("Date(2000) - 1", "Date(1999)"),
+        ("Date(2000) + 1", "Date(2001)"),
+
+#My great great grandfather died on 1876-05-07.
+#He died at an age of 65 years, 5 month 17 days according to the books:
+#> Date(1876,5,7)-(65,5,17)
+#1811-12-21
+#> Date(1876,5,7)-Date(1811,12,21)
+#(64, 4, 17)
+#But his correct birth date is 1810-11-20:
+#("Date(1876,5,7)-Date(1810,11,20)", "(65, 5, 18)")
+        ("Date(1876,5,7) - Date(1876,5,1)", "(0, 0, 6)"),
+        ("Date(1876,5,7) - Date(1876,4,30)", "(0, 0, 7)"),
+        ("Date(2000,1,1) - Date(1999,2,1)", "(0, 11, 0)"),
+        ("Date(2000,1,1) - Date(1999,12,1)", "(0, 1, 0)"),
+        # Date +/- Date -> tuple
+        ("Date(2007, 12, 23) - Date(1963, 12, 4)", "(44, 0, 19)"),
+        ]
+    suite = unittest.TestSuite()            
+    count = 1
+    for (exp1, exp2) in tests:
+        suite.addTest(Assert('test_assert%04d' % count, 1, exp1, exp2))
+        count += 1
+    return suite
+
 if __name__ == "__main__":
     unittest.TextTestRunner().run(suite())
+    unittest.TextTestRunner().run(suite2())