From b5d383a4be25ea517fa932c29406166495725495 Mon Sep 17 00:00:00 2001
From: Benjamin Bertrand <lafrite@poneyworld.net>
Date: Sat, 13 Feb 2016 19:47:35 +0300
Subject: [PATCH] Parse float and create Explicable_float

---
 pymath/calculus/explicable.py | 20 ++++++++++++++++++++
 pymath/calculus/expression.py |  6 +++++-
 pymath/calculus/str2tokens.py | 13 ++++++++++++-
 3 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/pymath/calculus/explicable.py b/pymath/calculus/explicable.py
index 8f8b9e2..d97b918 100644
--- a/pymath/calculus/explicable.py
+++ b/pymath/calculus/explicable.py
@@ -61,6 +61,7 @@ class Explicable(Renderable):
                 return False
 
 class Explicable_int(int, Explicable):
+    """ An Explicable_int is an int which can be explain """
     isNumber = True
 
     def __init__(self, val):
@@ -78,6 +79,25 @@ class Explicable_int(int, Explicable):
     def __tex__(self):
         return str(self._val)
 
+class Explicable_float(float, Explicable):
+    """ An Explicable_float is an float which can be explain """
+    isNumber = True
+
+    def __init__(self, val):
+        super(Explicable_float, self).__init__(val)
+        self._val = val
+        self.postfix_tokens = [self]
+        self.steps = []
+
+    def simplify(self):
+        return Explicable_float(self._val)
+
+    def __txt__(self):
+        return str(self._val)
+
+    def __tex__(self):
+        return str(self._val)
+
 
 
 # -----------------------------
diff --git a/pymath/calculus/expression.py b/pymath/calculus/expression.py
index 90c09cf..e8a0e26 100644
--- a/pymath/calculus/expression.py
+++ b/pymath/calculus/expression.py
@@ -7,7 +7,7 @@
 from .generic import Stack, flatten_list, expand_list, isNumber, isOperator, isNumerand
 from .str2tokens import str2tokens
 from .operator import op
-from .explicable import Explicable, Explicable_int
+from .explicable import Explicable, Explicable_int, Explicable_float
 
 from .random_expression import RdExpression
 
@@ -109,6 +109,10 @@ class Expression(Explicable):
             if isinstance(token, Explicable_int) or isinstance(token, int):
                 return Explicable_int(token)
 
+            # TODO: J'en arrive au soucis même soucis qu'avec les fractions qui une fois simplifiée devrait être des Explicable_int. Mais comment on ne redéfini pas les opérations, ce sont les opérations des int qui se font et donc on perd toute l'historique. |sam. févr. 13 18:57:45 EAT 2016
+            if isinstance(token, Explicable_float) or isinstance(token, float):
+                return Explicable_float(token)
+
             elif hasattr(token, 'simplify') and hasattr(token, 'explain'):
                 ans = expression.postfix_tokens[0]
                 return ans
diff --git a/pymath/calculus/str2tokens.py b/pymath/calculus/str2tokens.py
index fd7713d..4456ea3 100644
--- a/pymath/calculus/str2tokens.py
+++ b/pymath/calculus/str2tokens.py
@@ -45,6 +45,13 @@ def str2in_tokens(exp):
                 else:
                     tokens[-1] = tokens[-1] * 10 - int(character)
 
+            elif isinstance(tokens[-1], float):
+                after_coma += 1
+                if tokens[-1] >= 0:
+                    tokens[-1] = tokens[-1] + int(character) * 0.1 ** after_coma
+                else:
+                    tokens[-1] = tokens[-1]- int(character) * 0.1 ** after_coma
+
             # Special case for "-" at the begining of an expression or before
             # "("
             elif tokens[-1] == "-" and \
@@ -77,7 +84,11 @@ def str2in_tokens(exp):
             tokens.append(Polynom([0, 1], letter=character))
 
         elif character == ".":
-            raise ValueError("No float number please")
+            if isinstance(tokens[-1], float):
+                raise ValueError("A number has 2 points...!")
+            else:
+                tokens[-1] = float(tokens[-1])
+                after_coma = 0
 
         elif character != " ":
             raise ValueError("{} is an unvalid character".format(character))