#!/usr/bin/env python
# encoding: utf-8


import types
from .add import Add
from .div import Div
from .mul import Mul
from .par import Par
from .pw import Pw
from .sub import Sub
from .sub1 import Sub1


class Operator_set(object):
    """ Class for sets of operators"""

    def __init__(self):
        """ Initiate the operator_set """
        self._operators = {}

    def get_op(self, op, arity = 2):
        """Return the corresponding operator

        :op: symbole of the op
        :arity: the arity

        >>> op = Operator_set()
        >>> op.get_op('+')
        '+'
        >>> mul = op.get_op('*')
        >>> mul.tex
        '{op1} \\\\times {op2}'
        >>> mul.txt
        '{op1} * {op2}'
        """
        try:
            return getattr(self, self._operators[(op, arity)])
        except KeyError:
            raise KeyError("{theOp} (arity: {arity}) is not available".format(theOp = op, arity = arity))

    def can_be_operator(cls, symbole):
        """ Tell if the symbole can be an operator """
        if type(symbole) == str:
            return symbole in [i[0] for i in cls._operators]
        else:
            return False

    def store_operator(self, operator):
        """ Save the operator as a method and 

        :param operator: the operator (the class) (it will be accessible through .name method name.
        """
        # TODO: faire une vérif si on peut utiliser operator_name |mar. févr. 23 09:09:44 EAT 2016
        self._operators[operator.uniq_desc()] = operator.name
        setattr(self, operator.name, operator)


op = Operator_set()
op.store_operator(Add())
op.store_operator(Div())
op.store_operator(Mul())
op.store_operator(Par())
op.store_operator(Pw())
op.store_operator(Sub())
op.store_operator(Sub1())











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