From 976cbbdf03cd714f109a8310bd86a5208f4ad47e Mon Sep 17 00:00:00 2001
From: Benjamin Bertrand <lafrite@poneyworld.net>
Date: Mon, 7 Mar 2016 13:05:12 +0300
Subject: [PATCH] Merge_history (from Explicable) and develop_steps (from
 Expression) work together

---
 pymath/calculus/explicable.py | 30 +++++++++++++++++++------
 pymath/calculus/expression.py | 41 ++++++++++++++++++++---------------
 2 files changed, 47 insertions(+), 24 deletions(-)

diff --git a/pymath/calculus/explicable.py b/pymath/calculus/explicable.py
index bcb8558..9ac3dad 100644
--- a/pymath/calculus/explicable.py
+++ b/pymath/calculus/explicable.py
@@ -19,12 +19,12 @@ class Explicable(Renderable):
     def __init__(self, *args, **kwargs):
         super(Explicable, self).__init__()
         self.steps = []
-        self.explainator = 0
+        self.explained = 0
 
     def explain(self):
         r""" Generate and render steps  which leed to itself
 
-        After beening explained, the Explicable become amnesiac.
+        After beening explained, the Explicable become amnesiac. It will return itself in a list.
         See 'history_generator' to explain it once again.
 
         >>> action = Explicable()
@@ -39,12 +39,19 @@ class Explicable(Renderable):
         >>> # Now action is amnesiac
         >>> for i in action.explain():
         ...    print(i)
+        42
+        >>> action = Explicable()
+        >>> action.postfix_tokens = Expression('42')
+        >>> for i in action.explain():
+        ...    print(i)
+        42
 
         """
-        if not self.explainator:
-            self.explainator = self.history_generator()
-
-        return self.explainator
+        if self.explained:
+            return [self.STR_RENDER(self.postfix_tokens)]
+        else:
+            self.explained = 1
+            return self.history_generator()
 
     def history_generator(self):
         r""" Generator for rendered steps which leed to itself
@@ -145,9 +152,14 @@ class Explicable(Renderable):
         ['2 + 10 \\times 4', '2 \\times 12']
         ['2 + 40', '24']
         ['42', '24']
+        >>> # Now they are amnesiac
         >>> for i in action1.explain():
         ...    print(i)
-
+        42
+        >>> m_history = Explicable().merge_history([action1, action2])
+        >>> for i in m_history:
+        ...    print(i)
+        ['42', '24']
         >>> action1 = Explicable()
         >>> action1.postfix_tokens = Expression('42')
         >>> action1.this_append_before([Expression('2+10*4'), Expression('2+40')])
@@ -174,6 +186,10 @@ class Explicable(Renderable):
         ['2 + 10 \\times 4', '2 \\times 12', '3 - 3']
         ['2 + 40', '24', '0']
         ['42', '24', '0']
+        >>> m_history = Explicable().merge_history([1,2,3])
+        >>> for i in m_history:
+        ...    print(i)
+        [1, 2, 3]
         """
         steps = []
         for expl in explicables:
diff --git a/pymath/calculus/expression.py b/pymath/calculus/expression.py
index 79e8ace..863156e 100644
--- a/pymath/calculus/expression.py
+++ b/pymath/calculus/expression.py
@@ -252,25 +252,32 @@ class Expression(Explicable):
 
     @classmethod
     def develop_steps(cls, tokenList):
-        """ From a list of tokens, it develops steps of each tokens """
-        tmp_steps = []
-        for t in tokenList:
-            try:
-                with Expression.tmp_render():
-                    steps = [i for i in t.explain()]
-                    if steps:
-                        tmp_steps.append(steps)
-                    else:
-                        tmp_steps.append([t])
-            except AttributeError:
-                tmp_steps.append([t])
+        """ 
+        From a list of tokens, it develops steps of each tokens and transpose it into steps respecting the stucture of the tokenList.
 
-        if max([len(i) for i in tmp_steps]) > 1:
-            tmp_steps = expand_list(tmp_steps)[:-1]
-            steps = [Expression(s) for s in tmp_steps]
-            return steps
+        It try to use 'explain' method for every tokens. After using this methode, tokens becom amnesiac.
+        
+        >>> e = Expression('1+2')
+        >>> e1 = e.simplify()
+        >>> f = Expression('3*4+5')
+        >>> f1 = f.simplify()
+        >>> Expression.develop_steps([e1, f1, op.add])
+        [< <class 'pymath.calculus.expression.Expression'> [1, 2, +, 3, 4, *, 5, +, +] >, < <class 'pymath.calculus.expression.Expression'> [3, 12, 5, +, +] >]
+        >>> e = Expression('1+2')
+        >>> e1 = e.simplify()
+        >>> f = Expression('3*4+5')
+        >>> f1 = f.simplify()
+        >>> g = Expression('6+7')
+        >>> g1 = g.simplify()
+        >>> Expression.develop_steps([e1, f1, op.add, g1, op.mul])
+        [< <class 'pymath.calculus.expression.Expression'> [1, 2, +, 3, 4, *, 5, +, +, 6, 7, +, *] >, < <class 'pymath.calculus.expression.Expression'> [3, 12, 5, +, +, 13, *] >]
+        """
+        with Expression.tmp_render():
+            tmp_steps = list(Explicable().merge_history(tokenList))
 
-        return []
+        tmp_steps = list(tmp_steps)[:-1]
+        steps = [Expression(s) for s in tmp_steps]
+        return steps
 
     @classmethod
     def isExpression(cls, other):