Add more tests for compare and coercion in preparation for the coercion

overhaul.  Closes SF patch #102878.

Lib/test/test_coercion.py

@@ -0,0 +1,113 @@
+import copy
+import sys
+
+# Fake a number that implements numeric methods through __coerce__
+class CoerceNumber:
+    def __init__(self, arg):
+        self.arg = arg
+
+    def __repr__(self):
+        return '<CoerceNumber %s>' % repr(self.arg)
+
+    def __coerce__(self, other):
+        if isinstance(other, CoerceNumber):
+            return self.arg, other.arg
+        else:
+            return (self.arg, other)
+
+
+# Fake a number that implements numeric ops through methods.
+class MethodNumber:
+
+    def __init__(self,arg):
+        self.arg = arg
+
+    def __repr__(self):
+        return '<MethodNumber %s>' % repr(self.arg)
+
+    def __add__(self,other):
+        return self.arg + other
+
+    def __radd__(self,other):
+        return other + self.arg
+
+    def __sub__(self,other):
+        return self.arg - other
+
+    def __rsub__(self,other):
+        return other - self.arg
+
+    def __mul__(self,other):
+        return self.arg * other
+
+    def __rmul__(self,other):
+        return other * self.arg
+
+    def __div__(self,other):
+        return self.arg / other
+
+    def __rdiv__(self,other):
+        return other / self.arg
+
+    def __pow__(self,other):
+        return self.arg ** other
+
+    def __rpow__(self,other):
+        return other ** self.arg
+
+    def __mod__(self,other):
+        return self.arg % other
+
+    def __rmod__(self,other):
+        return other % self.arg
+
+    def __cmp__(self, other):
+        return cmp(self.arg, other)
+
+
+candidates = [ 2, 2.2, 2L, 2+4j, [1], (2,), None,
+               MethodNumber(1), CoerceNumber(8)]
+
+infix_binops = [ '+', '-', '*', '/', '**', '%' ]
+prefix_binops = [ 'divmod' ]
+
+def do_infix_binops():
+    for a in candidates:
+        for b in candidates:
+            for op in infix_binops:
+                print '%s %s %s' % (a, op, b),
+                try:
+                    x = eval('a %s b' % op)
+                except:
+                    error = sys.exc_info()[:2]
+                    print '... %s' % error[0]
+                else:
+                    print '=', x
+                try:
+                    z = copy.copy(a)
+                except copy.Error:
+                    z = a # assume it has no inplace ops
+                print '%s %s= %s' % (a, op, b),
+                try:
+                    exec('z %s= b' % op)
+                except:
+                    error = sys.exc_info()[:2]
+                    print '... %s' % error[0]
+                else:
+                    print '=>', z
+
+def do_prefix_binops():
+    for a in candidates:
+        for b in candidates:
+            for op in prefix_binops:
+                print '%s(%s, %s)' % (op, a, b),
+                try:
+                    x = eval('%s(a, b)' % op)
+                except:
+                    error = sys.exc_info()[:2]
+                    print '... %s' % error[0]
+                else:
+                    print '=', x
+
+do_infix_binops()
+do_prefix_binops()