Module src.olaaaf.formula.nullaryFormula.constraint.enumeratedType

Representation of an enumerated Type.

Classes

class EnumeratedType (name: str, values: list[str] = None)

Representation of a PropositionalVariable in CPC.

Parameters

name : str

The name of the enumerated type, either to get (if values is None) or to create.

values : list[str], optional

List of the names of the values the enumerated type can have.

Expand source code

class EnumeratedType:
    """
    Representation of a PropositionalVariable in CPC.

    Parameters
    ----------
    name : str
        The name of the enumerated type, either to get (if `values` is `None`) or to create.
    values : list[str], optional
        List of the names of the values the enumerated type can have.
    """

    name: str
    values: dict[str, PropositionalVariable]

    __instances = {}

    def __init__(self, name: str, values: list[str] = None):
        
        if values is None:
            self.name = name
            et = self.get(name)
            self.values = et.values
        elif len(values) >= 3:
            self.values = {val:PropositionalVariable("e2b_" + name + ":" + val) for val in values}
            self.name = name
        else:
            raise(AttributeError("values array should contain at least three elements"))


    @staticmethod
    def declare(name: str, values: list[str]):
        """
        Function to declare a new `EnumeratedType`, accessible either via the constructor or the `get()` function.

        Parameters
        ----------
        name : str
            The name of the enumerated type to declare.
        values : list[str]
            List of the names of the values the enumerated type can have.

        Returns
        -------
        `EnumeratedType`
            The newly declared enumerated type.

        """
        
        #TODO Check if name already declared
        newType = EnumeratedType(name, values)
        __class__.__instances[name] = newType

        return newType
    
    @staticmethod
    def get(name: str):
        """
        Function to get a previously declared `EnumeratedType`.

        Parameters
        ----------
        name : str
            The name of the enumerated type to get.

        Returns
        -------
        `EnumeratedType`
            The enumerated type to get.
        """

        # TODO check erreur
        return __class__.__instances[name]

    def __getitem__(self, key: str):

        # TODO check erreur
        return self.values[key]
    
    def generateConstraints(self):
        """
        Method to generate the necessary constraints to translate an enumerated type into multiple propositional constraints.

        Returns
        -------
        `olaaaf.formula.formula.Formula`
            The necessary constraints.
        """

        from ...naryFormula import And, Or

        propSet = self.values.values()
        
        constraints = Or(*propSet)

        for propTuple in combinations(propSet, len(propSet)-1):
            constraints &= ~And(*propTuple)

        return constraints
    
    def __eq__(self, o) -> bool:
        if o.__class__ != self.__class__:
            return False
        else:
            return (o.name == self.name)
        
    def __hash__(self):
        return hash(str(self))

Class variables

var name : str

var values : dict[str, PropositionalVariable]

Static methods

def declare(name: str, values: list[str])

Function to declare a new EnumeratedType, accessible either via the constructor or the get() function.

Parameters

name : str

The name of the enumerated type to declare.

values : list[str]

List of the names of the values the enumerated type can have.

Returns

EnumeratedType The newly declared enumerated type.

def get(name: str)

Function to get a previously declared EnumeratedType.

Parameters

name : str

The name of the enumerated type to get.

Returns

EnumeratedType The enumerated type to get.

Methods

def generateConstraints(self)

Method to generate the necessary constraints to translate an enumerated type into multiple propositional constraints.

Returns

olaaaf.formula.formula.Formula The necessary constraints.