From d88c8ff7381a2874328943e91dc7774913d52643 Mon Sep 17 00:00:00 2001
From: Lafrite <lafrite@poneyworld.net>
Date: Wed, 25 Feb 2015 15:23:01 +0100
Subject: [PATCH] Start working on parent class: Renderable_expression and
 Computable_expression

---
 pymath/computable_expression.py | 46 +++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 pymath/computable_expression.py

diff --git a/pymath/computable_expression.py b/pymath/computable_expression.py
new file mode 100644
index 0000000..59a513e
--- /dev/null
+++ b/pymath/computable_expression.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+# encoding: utf-8
+
+class Renderable_expression(object):
+
+    """Docstring for Renderable_expression. """
+
+    def __init__(self):
+        """@todo: to be defined1. """
+        
+
+
+
+class Computable_expression(Renderable_expression):
+
+    """ A computable_expression is an expression represented by a list of postfix tokens. It's a parent class of a more classical Expression, Fraction and Polynom (and later square root)
+    Child class will herits those methods
+        * simplify: Compute entirely the expression
+        * explain: Generator which return steps which leed to himself
+    
+    """
+
+    def __init__(self):
+        """@todo: to be defined1. """
+
+        pass
+
+    def simplify(self):
+        """ Simplify the expression
+
+        :returns: the simplified expression with .steps attributes where steps are stocked
+
+        """
+        pass
+
+    def explain(self):
+        """ Generate and render steps  which leed to itself """
+        pass
+        
+
+
+
+# -----------------------------
+# Reglages pour 'vim'
+# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
+# cursor: 16 del