Rename Expression class into LinExpr

diff --git a/linpy/__init__.py b/linpy/__init__.py
index 0ae2e66..2fdc73e 100644 (file)
--- a/linpy/__init__.py
+++ b/linpy/__init__.py
@@ -20,13 +20,13 @@ A polyhedral library based on ISL
 """
 
 from .geometry import Point, Vector
-from .linexprs import Expression, Symbol, Dummy, symbols, Rational
+from .linexprs import LinExpr, Symbol, Dummy, symbols, Rational
 from .polyhedra import Polyhedron, Eq, Ne, Le, Lt, Ge, Gt, Ne, Empty, Universe
 from .domains import Domain, And, Or, Not
 
 
 __all__ = [
-    'Expression', 'Symbol', 'Dummy', 'symbols', 'Rational',
+    'LinExpr', 'Symbol', 'Dummy', 'symbols', 'Rational',
     'Point', 'Vector',
     'Polyhedron', 'Eq', 'Ne', 'Le', 'Lt', 'Ge', 'Gt', 'Empty', 'Universe',
     'Domain', 'And', 'Or', 'Not',

diff --git a/linpy/domains.py b/linpy/domains.py
index 70e5e4f..238248b 100644 (file)
--- a/linpy/domains.py
+++ b/linpy/domains.py
@@ -31,7 +31,7 @@ from fractions import Fraction
 
 from . import islhelper
 from .islhelper import mainctx, libisl
-from .linexprs import Expression, Symbol, Rational
+from .linexprs import LinExpr, Symbol, Rational
 from .geometry import GeometricObject, Point, Vector
 
 
@@ -616,10 +616,10 @@ class Domain(GeometricObject):
         elif isinstance(node, ast.Compare):
             equalities = []
             inequalities = []
-            left = Expression._fromast(node.left)
+            left = LinExpr._fromast(node.left)
             for i in range(len(node.ops)):
                 op = node.ops[i]
-                right = Expression._fromast(node.comparators[i])
+                right = LinExpr._fromast(node.comparators[i])
                 if isinstance(op, ast.Lt):
                     inequalities.append(right - left - 1)
                 elif isinstance(op, ast.LtE):
@@ -642,7 +642,7 @@ class Domain(GeometricObject):
     _RE_AND = re.compile(r'\band\b|,|&&|/\\|∧|∩')
     _RE_OR = re.compile(r'\bor\b|;|\|\||\\/|∨|∪')
     _RE_NOT = re.compile(r'\bnot\b|!|¬')
-    _RE_NUM_VAR = Expression._RE_NUM_VAR
+    _RE_NUM_VAR = LinExpr._RE_NUM_VAR
     _RE_OPERATORS = re.compile(r'(&|\||~)')
 
     @classmethod
@@ -701,7 +701,7 @@ class Domain(GeometricObject):
             args = [Domain.fromsympy(arg) for arg in expr.args]
             return funcmap[expr.func](*args)
         elif isinstance(expr, sympy.Expr):
-            return Expression.fromsympy(expr)
+            return LinExpr.fromsympy(expr)
         raise ValueError('non-domain expression: {!r}'.format(expr))
 
     def tosympy(self):

diff --git a/linpy/linexprs.py b/linpy/linexprs.py
index bc36fda..8267be1 100644 (file)
--- a/linpy/linexprs.py
+++ b/linpy/linexprs.py
@@ -25,7 +25,7 @@ from fractions import Fraction, gcd
 
 
 __all__ = [
-    'Expression',
+    'LinExpr',
     'Symbol', 'Dummy', 'symbols',
     'Rational',
 ]
@@ -34,7 +34,7 @@ __all__ = [
 def _polymorphic(func):
     @functools.wraps(func)
     def wrapper(left, right):
-        if isinstance(right, Expression):
+        if isinstance(right, LinExpr):
             return func(left, right)
         elif isinstance(right, numbers.Rational):
             right = Rational(right)
@@ -43,7 +43,7 @@ def _polymorphic(func):
     return wrapper
 
 
-class Expression:
+class LinExpr:
     """
     This class implements linear expressions.
     """
@@ -55,7 +55,7 @@ class Expression:
         if isinstance(coefficients, str):
             if constant != 0:
                 raise TypeError('too many arguments')
-            return Expression.fromstring(coefficients)
+            return LinExpr.fromstring(coefficients)
         if coefficients is None:
             return Rational(constant)
         if isinstance(coefficients, Mapping):
@@ -163,7 +163,7 @@ class Expression:
         for symbol, coefficient in other._coefficients.items():
             coefficients[symbol] += coefficient
         constant = self._constant + other._constant
-        return Expression(coefficients, constant)
+        return LinExpr(coefficients, constant)
 
     __radd__ = __add__
 
@@ -176,7 +176,7 @@ class Expression:
         for symbol, coefficient in other._coefficients.items():
             coefficients[symbol] -= coefficient
         constant = self._constant - other._constant
-        return Expression(coefficients, constant)
+        return LinExpr(coefficients, constant)
 
     @_polymorphic
     def __rsub__(self, other):
@@ -190,7 +190,7 @@ class Expression:
             coefficients = ((symbol, coefficient * other)
                 for symbol, coefficient in self._coefficients.items())
             constant = self._constant * other
-            return Expression(coefficients, constant)
+            return LinExpr(coefficients, constant)
         return NotImplemented
 
     __rmul__ = __mul__
@@ -200,7 +200,7 @@ class Expression:
             coefficients = ((symbol, coefficient / other)
                 for symbol, coefficient in self._coefficients.items())
             constant = self._constant / other
-            return Expression(coefficients, constant)
+            return LinExpr(coefficients, constant)
         return NotImplemented
 
     @_polymorphic
@@ -208,7 +208,7 @@ class Expression:
         """
         Test whether two expressions are equal
         """
-        return isinstance(other, Expression) and \
+        return isinstance(other, LinExpr) and \
             self._coefficients == other._coefficients and \
             self._constant == other._constant
 
@@ -256,7 +256,7 @@ class Expression:
                 if othersymbol != symbol]
             coefficient = result._coefficients.get(symbol, 0)
             constant = result._constant
-            result = Expression(coefficients, constant) + coefficient*expression
+            result = LinExpr(coefficients, constant) + coefficient*expression
         return result
 
     @classmethod
@@ -292,7 +292,7 @@ class Expression:
         Create an expression from a string.
         """
         # add implicit multiplication operators, e.g. '5x' -> '5*x'
-        string = Expression._RE_NUM_VAR.sub(r'\1*\2', string)
+        string = LinExpr._RE_NUM_VAR.sub(r'\1*\2', string)
         tree = ast.parse(string, 'eval')
         return cls._fromast(tree)
 
@@ -368,11 +368,11 @@ class Expression:
                 coefficients.append((symbol, coefficient))
             else:
                 raise ValueError('non-linear expression: {!r}'.format(expr))
-        return Expression(coefficients, constant)
+        return LinExpr(coefficients, constant)
 
     def tosympy(self):
         """
-        Return an expression as a sympy object.  
+        Return an expression as a sympy object.
         """
         import sympy
         expr = 0
@@ -383,7 +383,7 @@ class Expression:
         return expr
 
 
-class Symbol(Expression):
+class Symbol(LinExpr):
 
     def __new__(cls, name):
         """
@@ -494,7 +494,7 @@ def symbols(names):
     return tuple(Symbol(name) for name in names)
 
 
-class Rational(Expression, Fraction):
+class Rational(LinExpr, Fraction):
     """
     This class represents integers and rational numbers of any size.
     """

diff --git a/linpy/polyhedra.py b/linpy/polyhedra.py
index 8eddb2d..346ffff 100644 (file)
--- a/linpy/polyhedra.py
+++ b/linpy/polyhedra.py
@@ -23,7 +23,7 @@ from . import islhelper
 
 from .islhelper import mainctx, libisl
 from .geometry import GeometricObject, Point
-from .linexprs import Expression, Rational
+from .linexprs import LinExpr, Rational
 from .domains import Domain
 
 
@@ -50,7 +50,7 @@ class Polyhedron(Domain):
         """
         Create and return a new Polyhedron from a string or list of equalities and inequalities.
         """
-        
+
         if isinstance(equalities, str):
             if inequalities is not None:
                 raise TypeError('too many arguments')
@@ -63,14 +63,14 @@ class Polyhedron(Domain):
             equalities = []
         else:
             for i, equality in enumerate(equalities):
-                if not isinstance(equality, Expression):
+                if not isinstance(equality, LinExpr):
                     raise TypeError('equalities must be linear expressions')
                 equalities[i] = equality.scaleint()
         if inequalities is None:
             inequalities = []
         else:
             for i, inequality in enumerate(inequalities):
-                if not isinstance(inequality, Expression):
+                if not isinstance(inequality, LinExpr):
                     raise TypeError('inequalities must be linear expressions')
                 inequalities[i] = inequality.scaleint()
         symbols = cls._xsymbols(equalities + inequalities)
@@ -191,7 +191,7 @@ class Polyhedron(Domain):
                 coefficient = islhelper.isl_val_to_int(coefficient)
                 if coefficient != 0:
                     coefficients[symbol] = coefficient
-            expression = Expression(coefficients, constant)
+            expression = LinExpr(coefficients, constant)
             if libisl.isl_constraint_is_equality(islconstraint):
                 equalities.append(expression)
             else:
@@ -345,13 +345,13 @@ Universe = UniverseType()
 def _polymorphic(func):
     @functools.wraps(func)
     def wrapper(left, right):
-        if not isinstance(left, Expression):
+        if not isinstance(left, LinExpr):
             if isinstance(left, numbers.Rational):
                 left = Rational(left)
             else:
                 raise TypeError('left must be a a rational number '
                     'or a linear expression')
-        if not isinstance(right, Expression):
+        if not isinstance(right, LinExpr):
             if isinstance(right, numbers.Rational):
                 right = Rational(right)
             else:

diff --git a/linpy/tests/test_linexprs.py b/linpy/tests/test_linexprs.py
index 16b9cde..fb7e4a2 100644 (file)
--- a/linpy/tests/test_linexprs.py
+++ b/linpy/tests/test_linexprs.py
@@ -24,34 +24,34 @@ from ..linexprs import *
 from .libhelper import requires_sympy
 
 
-class TestExpression(unittest.TestCase):
+class TestLinExpr(unittest.TestCase):
 
     def setUp(self):
         self.x = Symbol('x')
         self.y = Symbol('y')
         self.z = Symbol('z')
-        self.zero = Expression(constant=0)
-        self.one = Expression(constant=1)
-        self.pi = Expression(constant=Fraction(22, 7))
+        self.zero = LinExpr(constant=0)
+        self.one = LinExpr(constant=1)
+        self.pi = LinExpr(constant=Fraction(22, 7))
         self.expr = self.x - 2*self.y + 3
 
     def test_new(self):
-        self.assertIsInstance(Expression(coefficients={self.x: 1}), Symbol)
-        self.assertIsInstance(Expression(constant=self.pi), Rational)
+        self.assertIsInstance(LinExpr(coefficients={self.x: 1}), Symbol)
+        self.assertIsInstance(LinExpr(constant=self.pi), Rational)
         self.assertNotIsInstance(self.x + self.pi, Symbol)
         self.assertNotIsInstance(self.x + self.pi, Rational)
-        xx = Expression({self.x: 2})
+        xx = LinExpr({self.x: 2})
         self.assertNotIsInstance(xx, Symbol)
         with self.assertRaises(TypeError):
-            Expression('x + y', 2)
+            LinExpr('x + y', 2)
         with self.assertRaises(TypeError):
-            Expression({0: 2})
+            LinExpr({0: 2})
         with self.assertRaises(TypeError):
-            Expression({'x': '2'})
-        self.assertEqual(Expression(constant=1), Expression(constant=self.one))
-        self.assertEqual(Expression(constant='1'), Expression(constant=self.one))
+            LinExpr({'x': '2'})
+        self.assertEqual(LinExpr(constant=1), LinExpr(constant=self.one))
+        self.assertEqual(LinExpr(constant='1'), LinExpr(constant=self.one))
         with self.assertRaises(ValueError):
-            Expression(constant='a')
+            LinExpr(constant='a')
 
     def test_coefficient(self):
         self.assertEqual(self.expr.coefficient(self.x), 1)
@@ -174,15 +174,15 @@ class TestExpression(unittest.TestCase):
             self.expr.subs(self.x, 'x')
 
     def test_fromstring(self):
-        self.assertEqual(Expression.fromstring('x'), self.x)
-        self.assertEqual(Expression.fromstring('-x'), -self.x)
-        self.assertEqual(Expression.fromstring('22/7'), self.pi)
-        self.assertEqual(Expression.fromstring('x - 2y + 3'), self.expr)
-        self.assertEqual(Expression.fromstring('x - (3-1)y + 3'), self.expr)
-        self.assertEqual(Expression.fromstring('x - 2*y + 3'), self.expr)
+        self.assertEqual(LinExpr.fromstring('x'), self.x)
+        self.assertEqual(LinExpr.fromstring('-x'), -self.x)
+        self.assertEqual(LinExpr.fromstring('22/7'), self.pi)
+        self.assertEqual(LinExpr.fromstring('x - 2y + 3'), self.expr)
+        self.assertEqual(LinExpr.fromstring('x - (3-1)y + 3'), self.expr)
+        self.assertEqual(LinExpr.fromstring('x - 2*y + 3'), self.expr)
 
     def test_repr(self):
-        self.assertEqual(str(Expression()), '0')
+        self.assertEqual(str(LinExpr()), '0')
         self.assertEqual(str(self.x), 'x')
         self.assertEqual(str(-self.x), '-x')
         self.assertEqual(str(self.pi), '22/7')
@@ -192,11 +192,11 @@ class TestExpression(unittest.TestCase):
     def test_fromsympy(self):
         import sympy
         sp_x, sp_y = sympy.symbols('x y')
-        self.assertEqual(Expression.fromsympy(sp_x), self.x)
-        self.assertEqual(Expression.fromsympy(sympy.Rational(22, 7)), self.pi)
-        self.assertEqual(Expression.fromsympy(sp_x - 2*sp_y + 3), self.expr)
+        self.assertEqual(LinExpr.fromsympy(sp_x), self.x)
+        self.assertEqual(LinExpr.fromsympy(sympy.Rational(22, 7)), self.pi)
+        self.assertEqual(LinExpr.fromsympy(sp_x - 2*sp_y + 3), self.expr)
         with self.assertRaises(ValueError):
-            Expression.fromsympy(sp_x*sp_y)
+            LinExpr.fromsympy(sp_x*sp_y)
 
     @requires_sympy
     def test_tosympy(self):