From 1176b6f6082aaffddf4b37b3d9602ce41cc7a6e8 Mon Sep 17 00:00:00 2001
From: Bertrand Benjamin <benjamin.bertrand@opytex.org>
Date: Sun, 21 Jan 2018 18:16:08 +0300
Subject: [PATCH] Basic evaluation for trees

---
 mapytex/calculus/core/evaluate.py | 46 +++++++++++++++++++++++++++++++
 mapytex/calculus/core/operator.py | 32 +++++++++++++++++----
 mapytex/calculus/core/tree.py     | 14 +++++++++-
 3 files changed, 85 insertions(+), 7 deletions(-)
 create mode 100644 mapytex/calculus/core/evaluate.py

diff --git a/mapytex/calculus/core/evaluate.py b/mapytex/calculus/core/evaluate.py
new file mode 100644
index 0000000..3e2f75a
--- /dev/null
+++ b/mapytex/calculus/core/evaluate.py
@@ -0,0 +1,46 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+# vim:fenc=utf-8
+#
+# Copyright © 2017 lafrite <lafrite@Poivre>
+#
+# Distributed under terms of the MIT license.
+
+"""
+Evaluating a binary tree
+"""
+
+from .operator import OPERATORS
+
+def compute(node, left_v, right_v):
+    """ 
+    Computing a node 
+
+    :example:
+
+    >>> compute("+", 1, 2)
+    3
+    >>> compute("-", 1, 2)
+    -1
+    >>> compute("-", None, 2)
+    -2
+
+    """
+    op = OPERATORS[node]
+    lv = left_v
+    rv = right_v
+    if lv is None:
+        return op["_operate"](rv)()
+    
+    try:
+        return op["operate"](lv)(rv)
+    except NotImplemented:
+        return op["roperate"](rv)(lv)
+
+
+
+
+# -----------------------------
+# Reglages pour 'vim'
+# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
+# cursor: 16 del
diff --git a/mapytex/calculus/core/operator.py b/mapytex/calculus/core/operator.py
index 34781fa..21ce8d8 100644
--- a/mapytex/calculus/core/operator.py
+++ b/mapytex/calculus/core/operator.py
@@ -6,13 +6,33 @@
 #
 # Distributed under terms of the MIT license.
 
-
 OPERATORS = {
-    "+": {"priority":0},
-    "-": {"priority":1},
-    "*": {"priority":2},
-    "/": {"priority":3},
-    "^": {"priority":4},
+        "+": {'repr': "+",
+            'precedence': 0,
+            'operate': lambda x: x.__getattribute__("__add__"),
+            'roperate': lambda x: x.__getattribute__("__radd__"),
+            },
+        "-": {'repr': "-",
+            'precedence': 1,
+            '_operate': lambda x: x.__getattribute__("__neg__"),
+            'operate': lambda x: x.__getattribute__("__sub__"),
+            'roperate': lambda x: x.__getattribute__("__rsub__"),
+            },
+        "*": {'repr': "*",
+            'precedence': 2,
+            'operate': lambda x: x.__getattribute__("__mul__"),
+            'roperate': lambda x: x.__getattribute__("__rmul__"),
+            },
+        "/": {'repr': "/",
+            'precedence': 3,
+            'operate': lambda x: x.__getattribute__("__div__"),
+            'roperate': lambda x: x.__getattribute__("__rdiv__"),
+            },
+        "^": {'repr': "^",
+            'precedence': 4,
+            'operate': lambda x: x.__getattribute__("__pow__"),
+            'roperate': lambda x: x.__getattribute__("__rpow__"),
+            },
 }
 
 
diff --git a/mapytex/calculus/core/tree.py b/mapytex/calculus/core/tree.py
index f2b99c9..7a1f13c 100644
--- a/mapytex/calculus/core/tree.py
+++ b/mapytex/calculus/core/tree.py
@@ -243,7 +243,15 @@ class Tree(object):
         +
          > 3 * 4
          > 2
-
+        >>> from .evaluate import compute
+        >>> tt = t.apply_on_last_level(compute)
+        >>> print(tt)
+        +
+         > 12
+         > 2
+        >>> ttt = tt.apply_on_last_level(compute)
+        >>> print(ttt)
+        14
         """
         left_is_leaf = 0
         right_is_leaf = 0
@@ -286,6 +294,10 @@ class Tree(object):
         >>> t.apply(to_nested)
         ('+', (('*', (3, 4)), 2))
 
+        >>> from .evaluate import compute
+        >>> t.apply(compute)
+        14
+
         """
         try:
             left_value = self.left_value.apply(function)