Multiply with MOnumber and MOFraction

mapytex/calculus/core/compute/exceptions.py

@@ -16,6 +16,9 @@ class ComputeError(Exception):
 class AddError(ComputeError):
     pass
 
+class MultiplyError(ComputeError):
+    pass
+
 
 # -----------------------------
 # Reglages pour 'vim'

mapytex/calculus/core/compute/multiply.py

@@ -0,0 +1,135 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+# vim:fenc=utf-8
+#
+# Copyright © 2017 lafrite <lafrite@Poivre>
+#
+# Distributed under terms of the MIT license.
+
+"""
+Multiply MO
+"""
+
+from ..tree import Tree
+from ..operator import OPERATORS
+from ..MO.mo import MO, MOnumber, MOstr
+from ..MO.fraction import MOFraction
+from .exceptions import MultiplyError
+
+
+def multiply(left, right):
+    """ Perform the addition of left and right
+
+    :param left: left MO
+    :param right: right MO
+    :returns: Tree or MO
+
+    >>> a = MOnumber(4)
+    >>> b = MOnumber(6)
+    >>> multiply(a, b)
+    <MOnumber 24>
+    >>> b = MOnumber(0)
+    >>> multiply(a, b)
+    <MOnumber 0>
+
+    """
+    if left.value == 0 or right.value ==  0:
+        return MOnumber(0)
+    elif left.value ==  1:
+        return right
+    elif right.value ==  1:
+        return left
+
+    return MULFUNCTIONS[(type(left), type(right))](left, right)
+
+def monumber_monumber(left, right):
+    """ Multiply 2 monumbers
+
+    :param left: left MOnumber
+    :param right: right MOnumber
+    :returns: MONumber
+
+    >>> a = MOnumber(4)
+    >>> b = MOnumber(6)
+    >>> monumber_monumber(a, b)
+    <MOnumber 24>
+
+    """
+    return MO.factory(left.value * right.value)
+
+def monumber_mofraction(left, right):
+    """ Multiply a monumber and a mofraction
+
+    :param left: a monumber
+    :param right: a mofraction
+    :returns: Tree with the multiplication on the numerator
+
+    >>> a = MOnumber(4)
+    >>> b = MOFraction(6, 5)
+    >>> print(monumber_mofraction(a, b))
+    /
+     > *
+     | > 4
+     | > 6
+     > 5
+    >>> b = MOFraction(6, 5, True)
+    >>> print(monumber_mofraction(a, b))
+    -
+     > None
+     > /
+     | > *
+     | | > 4
+     | | > 6
+     | > 5
+
+    """
+    if not isinstance(left, MOnumber) or not isinstance(right, MOFraction):
+        raise MultiplyError(f"Wrong type for left (got {left.__class__.__name__}) \
+                or right (got {right.__class__.__name__})")
+
+    num = Tree("*", left, right._numerator)
+    frac =  Tree("/", num, right._denominator)
+    if right.negative:
+        return Tree("-", None, frac)
+
+    return frac
+
+def mofraction_monumber(left, right):
+    """ Adding a monumber and a mofraction
+
+    :param left: a mofraction
+    :param right: a monumber
+    :returns: Tree with the number converted into a mofraction
+
+    >>> a = MOFraction(6, 5)
+    >>> b = MOnumber(4)
+    >>> print(mofraction_monumber(a, b))
+    /
+     > *
+     | > 6
+     | > 4
+     > 5
+    """
+
+    if not isinstance(left, MOFraction) or not isinstance(right, MOnumber):
+        raise MultiplyError(f"Wrong type for left (got {left.__class__.__name__})"
+                f"or right (got {right.__class__.__name__})")
+
+    num = Tree("*", left._numerator, right)
+    frac =  Tree("/", num, left._denominator)
+    if left.negative:
+        return Tree("-", None, frac)
+
+    return frac
+
+# TODO: Faire un décorateur pour un enregistrement automatique |dim. mars 11 18:24:32 EAT 2018
+MULFUNCTIONS = {
+        (MOnumber, MOnumber): monumber_monumber,
+        (MOnumber, MOFraction): monumber_mofraction,
+        (MOFraction, MOnumber): mofraction_monumber,
+        }
+
+# -----------------------------
+# Reglages pour 'vim'
+# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
+# cursor: 16 del