From 2b1e012ff2ad875e44e368bc37430ac5e5e97324 Mon Sep 17 00:00:00 2001
From: Vivien Maisonneuve <v.maisonneuve@gmail.com>
Date: Tue, 24 Jun 2014 10:54:34 +0200
Subject: [PATCH] Change string representations of Expression and Polyhedron

---
 pypol/linear.py      | 15 +++------------
 tests/test_linear.py | 35 ++++++++++++++++++++++++++++++++---
 2 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/pypol/linear.py b/pypol/linear.py
index 74b5477..b40415f 100644
--- a/pypol/linear.py
+++ b/pypol/linear.py
@@ -285,13 +285,7 @@ class Expression:
             return '({})'.format(string)
 
     def __repr__(self):
-        string = '{}({{'.format(self.__class__.__name__)
-        for i, (symbol, coefficient) in enumerate(self.coefficients()):
-            if i != 0:
-                string += ', '
-            string += '{!r}: {!r}'.format(symbol, coefficient)
-        string += '}}, {!r})'.format(self.constant)
-        return string
+        return '{}({!r})'.format(self.__class__.__name__, str(self))
 
     @_polymorphic_method
     def __eq__(self, other):
@@ -673,7 +667,7 @@ class Polyhedron:
             constraints.append('{} == 0'.format(constraint))
         for constraint in self.inequalities:
             constraints.append('{} >= 0'.format(constraint))
-        return '{{{}}}'.format(', '.join(constraints))
+        return '{}'.format(', '.join(constraints))
 
     def __repr__(self):
         if self.isempty():
@@ -681,10 +675,7 @@ class Polyhedron:
         elif self.isuniverse():
             return 'Universe'
         else:
-            equalities = list(self.equalities)
-            inequalities = list(self.inequalities)
-            return '{}(equalities={!r}, inequalities={!r})' \
-                    ''.format(self.__class__.__name__, equalities, inequalities)
+            return '{}({!r})'.format(self.__class__.__name__, str(self))
 
     @classmethod
     def _fromsympy(cls, expr):
diff --git a/tests/test_linear.py b/tests/test_linear.py
index f02c4f4..ce42473 100644
--- a/tests/test_linear.py
+++ b/tests/test_linear.py
@@ -148,7 +148,8 @@ class TestExpression(unittest.TestCase):
         self.assertEqual(repr(self.x), "Symbol('x')")
         self.assertEqual(repr(self.one), 'Constant(1)')
         self.assertEqual(repr(self.pi), 'Constant(22, 7)')
-        self.assertEqual(repr(self.expr), "Expression({'x': 1, 'y': -2}, 3)")
+        self.assertEqual(repr(self.x + self.one), "Expression('x + 1')")
+        self.assertEqual(repr(self.expr), "Expression('x - 2*y + 3')")
 
     def test_fromstring(self):
         self.assertEqual(Expression.fromstring('x'), self.x)
@@ -241,9 +242,13 @@ class TestPolyhedron(unittest.TestCase):
     def test_dimension(self):
         self.assertEqual(self.square.dimension, 2)
 
-    def test_tostring(self):
+    def test_str(self):
         self.assertEqual(str(self.square),
-            '{x >= 0, -x + 1 >= 0, y >= 0, -y + 1 >= 0}')
+            'x >= 0, -x + 1 >= 0, y >= 0, -y + 1 >= 0')
+
+    def test_repr(self):
+        self.assertEqual(repr(self.square),
+            "Polyhedron('x >= 0, -x + 1 >= 0, y >= 0, -y + 1 >= 0')")
 
     def test_fromstring(self):
         self.assertEqual(Polyhedron.fromstring('{x >= 0, -x + 1 >= 0, '
@@ -267,3 +272,27 @@ class TestPolyhedron(unittest.TestCase):
         sp_x, sp_y = sympy.symbols('x y')
         self.assertEqual(self.square.tosympy(),
             sympy.And(-sp_x + 1 >= 0, -sp_y + 1 >= 0, sp_x >= 0, sp_y >= 0))
+
+
+class TestEmpty:
+
+    def test_repr(self):
+        self.assertEqual(repr(Empty), 'Empty')
+
+    def test_isempty(self):
+        self.assertTrue(Empty.isempty())
+
+    def test_isuniverse(self):
+        self.assertFalse(Empty.isuniverse())
+
+
+class TestUniverse:
+
+    def test_repr(self):
+        self.assertEqual(repr(Universe), 'Universe')
+
+    def test_isempty(self):
+        self.assertTrue(Universe.isempty())
+
+    def test_isuniverse(self):
+        self.assertTrue(Universe.isuniverse())
-- 
2.20.1