Rename Expression class into LinExpr

[linpy.git] / linpy / linexprs.py

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.
     """