Module clingo.util

Utility functions and classes.

Classes

class Slice (slc: slice,
rec: ForwardRef('Slice') | None = None)

Expand source code

class Slice:
    """
    Wrapper for Python's slice that computes index ranges to slice sequences.

    Currently, the range is recomputed each time. It is probably also possible
    to combine the involved slices into one.
    """

    def __init__(self, slc: slice, rec: Optional["Slice"] = None):
        self._slc = slc
        self._rec = rec

    def rng(self, size):
        """
        Return a range providing indices to access a sequence of length size.
        """
        return (
            range(*self._slc.indices(size))
            if self._rec is None
            else self._rec.rng(size)[self._slc]
        )

Wrapper for Python's slice that computes index ranges to slice sequences.

Currently, the range is recomputed each time. It is probably also possible to combine the involved slices into one.

Methods

def rng(self, size)

Expand source code

def rng(self, size):
    """
    Return a range providing indices to access a sequence of length size.
    """
    return (
        range(*self._slc.indices(size))
        if self._rec is None
        else self._rec.rng(size)[self._slc]
    )

Return a range providing indices to access a sequence of length size.

class SlicedMutableSequence (seq: ,
slc: Slice)

Expand source code

class SlicedMutableSequence(SlicedSequence, abc.MutableSequence):
    """
    Helper to slice sequences.
    """

    def __init__(self, seq: abc.MutableSequence, slc: Slice):
        super().__init__(seq, slc)

    @property
    def _mut_seq(self):
        return cast(abc.MutableSequence, self._seq)

    def __setitem__(self, index, ast):
        if isinstance(index, slice):
            raise TypeError("slicing not implemented")
        self._mut_seq[self._rng[index]] = ast

    def __delitem__(self, index):
        if isinstance(index, slice):
            raise TypeError("slicing not implemented")
        del self._mut_seq[self._rng[index]]

    def insert(self, index, value):
        self._mut_seq[self._rng[index]] = value

Helper to slice sequences.

Ancestors

• SlicedSequence
• collections.abc.MutableSequence
• collections.abc.Sequence
• collections.abc.Reversible
• collections.abc.Collection
• collections.abc.Sized
• collections.abc.Iterable
• collections.abc.Container

Methods

def insert(self, index, value)

Expand source code

def insert(self, index, value):
    self._mut_seq[self._rng[index]] = value

S.insert(index, value) – insert value before index

class SlicedSequence (seq: ,
slc: Slice)

Expand source code

class SlicedSequence(abc.Sequence):
    """
    Helper to slice sequences.
    """

    def __init__(self, seq: abc.Sequence, slc: Slice):
        self._seq = seq
        self._slc = slc
        self._len = -1
        self._lst = None

    @property
    def _rng(self):
        size = len(self._seq)
        if size != self._len:
            self._lst = self._slc.rng(size)
            self._len = size
        return self._lst

    def __len__(self) -> int:
        return len(self._rng)

    def __iter__(self):
        for idx in self._rng:
            yield self._seq[idx]

    def __getitem__(self, slc):
        if isinstance(slc, slice):
            return SlicedSequence(self._seq, Slice(slc, self._slc))
        return self._seq[self._rng[slc]]

    def __str__(self):
        return str(list(self))

    def __repr__(self):
        return repr(list(self))

Helper to slice sequences.

Ancestors

• collections.abc.Sequence
• collections.abc.Reversible
• collections.abc.Collection
• collections.abc.Sized
• collections.abc.Iterable
• collections.abc.Container

Subclasses

• SlicedMutableSequence