From 7feca92d773b7d74f9dbd4ce004ce34e056c43fd Mon Sep 17 00:00:00 2001
From: Benjamin Bertrand <lafrite@poneyworld.net>
Date: Tue, 15 Mar 2016 12:43:34 +0300
Subject: [PATCH] move no_repetition in decorators

all test are passed
---
 pymath/calculus/decorators.py | 58 +++++++++++++++++++++++++++++++++++
 pymath/calculus/explicable.py | 25 +++------------
 2 files changed, 62 insertions(+), 21 deletions(-)
 create mode 100644 pymath/calculus/decorators.py

diff --git a/pymath/calculus/decorators.py b/pymath/calculus/decorators.py
new file mode 100644
index 0000000..d533968
--- /dev/null
+++ b/pymath/calculus/decorators.py
@@ -0,0 +1,58 @@
+#!/usr/bin/env python
+# encoding: utf-8
+
+from functools import wraps
+
+def is_same_step(new, old):
+    """Return whether the new step is the same than old step
+    """
+    try:
+        if new.replace(" ", "") == old.replace(" ", ""):
+            return True
+        else:
+            return False
+    except AttributeError:
+        if new == old:
+            return True
+        else:
+            return False
+
+def no_repetition(equals=lambda x,y: x == y):
+    """ Remove yield values which has already been yield
+
+    :param fun: a generator
+    :returns: same generator with no repetitions
+
+    >>> norep = no_repetition()
+    >>> def str_gene(string):
+    ...    for i in string:
+    ...        yield i
+    >>> norep_str_gene = norep(str_gene)
+    >>> [i for i in norep_str_gene("aaabraabbbere")]
+    ['a', 'b', 'r', 'a', 'b', 'e', 'r', 'e']
+
+    """
+    def wrapper(fun):
+        @wraps(fun)
+        def dont_repeat(*args, **kwrds):
+            gen = fun(*args, **kwrds)
+            old_s = ""
+            while True:
+                try:
+                    new_s = next(gen)
+                except StopIteration:
+                    break
+                else:
+                    if not equals(new_s, old_s):
+                        old_s = new_s
+                        yield new_s
+
+        return dont_repeat
+    return wrapper
+
+
+
+# -----------------------------
+# Reglages pour 'vim'
+# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
+# cursor: 16 del
diff --git a/pymath/calculus/explicable.py b/pymath/calculus/explicable.py
index de209ef..0a54f1c 100644
--- a/pymath/calculus/explicable.py
+++ b/pymath/calculus/explicable.py
@@ -5,6 +5,7 @@ from .renderable import Renderable
 from .step import Step
 from decimal import Decimal
 from .generic import transpose_fill
+from .decorators import is_same_step, no_repetition
 
 
 class Explicable(Renderable):
@@ -56,6 +57,7 @@ class Explicable(Renderable):
         """ Generator which yield itself rendered """
         yield self.STR_RENDER(self.postfix_tokens)
 
+    @no_repetition(is_same_step)
     def history_generator(self):
         r""" Generator for rendered steps which leed to itself
 
@@ -79,39 +81,20 @@ class Explicable(Renderable):
         2 + 40
         42
         """
-        old_s = ''
         try:
             for s in self.steps:
                 try:
                     new_s = self.STR_RENDER(s.postfix_tokens)
                 except AttributeError:
                     new_s = self.STR_RENDER(s)
-
-                if not self.is_same_step(new_s, old_s):
-                    old_s = new_s
-                    yield new_s
+                yield new_s
 
         except AttributeError:
             pass
 
         # if noself:
         new_s = self.STR_RENDER(self.postfix_tokens)
-        if not self.is_same_step(new_s, old_s):
-            yield new_s
-
-    def is_same_step(self, new, old):
-        """Return whether the new step is the same than old step
-        """
-        try:
-            if new.replace(" ", "") == old.replace(" ", ""):
-                return True
-            else:
-                return False
-        except AttributeError:
-            if new == old:
-                return True
-            else:
-                return False
+        yield new_s
 
     def this_append_before(self, steps):
         """ Add steps at the beginning of self.steps