py: Add dispatch for user defined ==, >, <=, >=.

Addresses issue #827.

py/objtype.c

@@ -381,11 +381,12 @@ STATIC const qstr binary_op_method_name[] = {
     MP_BINARY_OP_INPLACE_MODULO,
     MP_BINARY_OP_INPLACE_POWER,*/
     [MP_BINARY_OP_LESS] = MP_QSTR___lt__,
-    /*MP_BINARY_OP_MORE,
-    MP_BINARY_OP_EQUAL,
-    MP_BINARY_OP_LESS_EQUAL,
-    MP_BINARY_OP_MORE_EQUAL,
-    MP_BINARY_OP_NOT_EQUAL,
+    [MP_BINARY_OP_MORE] = MP_QSTR___gt__,
+    [MP_BINARY_OP_EQUAL] = MP_QSTR___eq__,
+    [MP_BINARY_OP_LESS_EQUAL] = MP_QSTR___le__,
+    [MP_BINARY_OP_MORE_EQUAL] = MP_QSTR___ge__,
+    /*
+    MP_BINARY_OP_NOT_EQUAL, // a != b calls a == b and inverts result
     */
     [MP_BINARY_OP_IN] = MP_QSTR___contains__,
     /*

py/qstrdefs.h

@@ -64,6 +64,10 @@ Q(__getattr__)
 Q(__del__)
 Q(__call__)
 Q(__lt__)
+Q(__gt__)
+Q(__eq__)
+Q(__le__)
+Q(__ge__)
 
 Q(micropython)
 Q(bytecode)

tests/basics/class_binop.py

+class foo(object):
+    def __init__(self, value):
+        self.x = value
+
+    def __eq__(self, other):
+        print('eq')
+        return self.x == other.x
+
+    def __lt__(self, other):
+        print('lt')
+        return self.x < other.x
+
+    def __gt__(self, other):
+        print('gt')
+        return self.x > other.x
+
+    def __le__(self, other):
+        print('le')
+        return self.x <= other.x
+
+    def __ge__(self, other):
+        print('ge')
+        return self.x >= other.x
+
+for i in range(3):
+    for j in range(3):
+        print(foo(i) == foo(j))
+        print(foo(i) < foo(j))
+        print(foo(i) > foo(j))
+        print(foo(i) <= foo(j))
+        print(foo(i) >= foo(j))