canonical_groups#

t3toolbox.backend.sharing.canonical_groups(sharing, shape)#
def canonical_groups(
        sharing:  typ.Optional[typ.Sequence],   # len=d group labels, or None
        shape:    typ.Tuple[int, ...],          # the mode sizes (group members must agree)
) -> typ.Tuple[typ.Tuple[int, ...], ...]:       # canonical partition, () when there is nothing to tie

Normalize a sharing spec to a canonical partition, collapsing “nothing is tied” to ().

None and an all-singleton partition both give (), so a consumer that stores the partition has exactly ONE representation of the unshared case – which matters when the partition is part of an object’s value identity (a jit aux_data key). validate_sharing() + nontrivial_groups() do the work; this just names the pairing, which callers otherwise open-code.

Parameters:

  • sharing (t3toolbox.backend.common.typ.Optional[t3toolbox.backend.common.typ.Sequence])

  • shape (t3toolbox.backend.common.typ.Tuple[int, ...])

Return type:

t3toolbox.backend.common.typ.Tuple[t3toolbox.backend.common.typ.Tuple[int, …], …]