Use multipledispatch for multiply

mapytex/calculus/core/compute/multiply.py

@@ -10,6 +10,7 @@
 Multiply MO
 """
 
+from multipledispatch import Dispatcher
 from ..tree import Tree
 from ..MO.mo import MO, MOnumber, MOstr
 from ..MO.fraction import MOFraction
@@ -17,66 +18,42 @@ from ..MO.monomial import MOMonomial
 from .exceptions import MultiplyError
 from .type_filter import args_are
 
-
+multiply_doc = """ Multiply MOs
-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)
+multiply = Dispatcher("multiply", doc=multiply_doc)
 
-@args_are(MOnumber, MOnumber)
+@multiply.register(MOnumber, MOnumber)
 def monumber_monumber(left, right):
-    """ Multiply 2 monumbers
+    """ Simply multiply values
-
-    :param left: left MOnumber
-    :param right: right MOnumber
-    :returns: MONumber
 
     >>> a = MOnumber(4)
     >>> b = MOnumber(6)
-    >>> monumber_monumber(a, b)
+    >>> multiply(a, b)
     <MOnumber 24>
 
     """
     return MO.factory(left.value * right.value)
 
-@args_are(MOnumber, MOFraction)
+@multiply.register(MOnumber, MOFraction)
 def monumber_mofraction(left, right):
-    """ Multiply a monumber and a mofraction
+    """ Return division Tree with on the numertor MOnumber times numerator of 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))
+    >>> print(multiply(a, b))
     /
      > *
      | > 4
      | > 6
      > 5
     >>> b = MOFraction(6, 5, True)
-    >>> print(monumber_mofraction(a, b))
+    >>> print(multiply(a, b))
     /
      > *
      | > 4
@@ -86,49 +63,32 @@ def monumber_mofraction(left, right):
      > 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)
     return Tree("/", num, right._denominator)
 
-@args_are(MOFraction, MOnumber)
+@multiply.register(MOFraction, MOnumber)
 def mofraction_monumber(left, right):
-    """ Multiply a monumber and a mofraction
+    """ Return division Tree with on the numertor MOnumber times numerator of 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))
+    >>> print(multiply(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)
     return Tree("/", num, left._denominator)
 
-@args_are(MOFraction, MOFraction)
+@multiply.register(MOFraction, MOFraction)
 def mofraction_mofraction(left, right):
-    """ Multiply two mofractions
+    """ Multiply two mofractions (numertors together and denominators together)
-
-    :param left: a mofraction
-    :param right: a mofraction
-    :returns: Tree with a new calculus
 
     >>> a = MOFraction(1, 5)
     >>> b = MOFraction(4, 5)
-    >>> print(mofraction_mofraction(a, b))
+    >>> print(multiply(a, b))
     /
      > *
      | > 1
@@ -137,63 +97,50 @@ def mofraction_mofraction(left, right):
      | > 5
      | > 5
     """
-
-    if not isinstance(left, MOFraction) or not isinstance(right, MOFraction):
-        raise AddError(f"Wrong type for left (got {left.__class__.__name__})"
-                f"or right (got {right.__class__.__name__})")
-
     num = Tree("*", left.numerator, right.numerator)
     denom = Tree("*", left.denominator, right.denominator)
     return Tree("/", num, denom)
 
-@args_are((MOnumber, MOFraction), MOstr)
+@multiply.register((MOnumber, MOFraction), MOstr)
 def moscalar_mostr(left, right):
-    """ Multiply a scalar with a letter
+    """ Multiply a scalar with a letter to create a MOMonomial
 
     >>> a = MOnumber(2)
     >>> b = MOstr('x')
-    >>> moscalar_mostr(a, b)
+    >>> multiply(a, b)
     <MOMonomial 2x>
     >>> a = MOFraction(1, 5)
-    >>> moscalar_mostr(a, b)
+    >>> multiply(a, b)
     <MOMonomial 1 / 5x>
     """
     return MOMonomial(left, right)
 
-@args_are(MOstr, (MOnumber, MOFraction))
+@multiply.register(MOstr, (MOnumber, MOFraction))
 def mostr_moscalar(left, right):
-    """ Multiply a scalar with a letter
+    """ Multiply a scalar with a letter to create a MOMonomial
 
     >>> a = MOstr('x')
     >>> b = MOnumber(2)
-    >>> mostr_moscalar(a, b)
+    >>> multiply(a, b)
     <MOMonomial 2x>
     >>> b = MOFraction(1, 5)
-    >>> mostr_moscalar(a, b)
+    >>> multiply(a, b)
     <MOMonomial 1 / 5x>
     """
     return MOMonomial(right, left)
 
-@args_are((MOnumber, MOFraction), MOMonomial)
+@multiply.register((MOnumber, MOFraction), MOMonomial)
 def moscalar_monomonial(left, right):
     """ Multiply a scalar with a monomial
 
     >>> a = MOnumber(4)
     >>> b = MOMonomial(5, 'x', 3)
 
-    # >>> print(moscalar_monomonial(a, b))
+    # >>> print(multiply(a, b))
     """
     coefficient = Tree('*', left, right._coefficient)
     return Tree('*', coefficient, MOMonomial(1, right._variable, right._power))
 
-# 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,
-    (MOFraction, MOFraction): mofraction_mofraction,
-    }
-
 # -----------------------------
 # Reglages pour 'vim'
 # vim:set autoindent expandtab tabstop=4 shiftwidth=4: