use std::cmp::Ordering;
use crate::fst_properties::FstProperties;
use crate::fst_traits::MutableFst;
use crate::semirings::Semiring;
use crate::{StateId, Tr};
pub trait TrCompare {
fn compare<W: Semiring>(a: &Tr<W>, b: &Tr<W>) -> Ordering;
fn properties(inprops: FstProperties) -> FstProperties;
}
pub struct ILabelCompare {}
impl TrCompare for ILabelCompare {
fn compare<W: Semiring>(a: &Tr<W>, b: &Tr<W>) -> Ordering {
a.ilabel.cmp(&b.ilabel)
}
fn properties(inprops: FstProperties) -> FstProperties {
let mut outprops =
(inprops & FstProperties::arcsort_properties()) | FstProperties::I_LABEL_SORTED;
if inprops.contains(FstProperties::ACCEPTOR) {
outprops |= FstProperties::O_LABEL_SORTED;
}
outprops
}
}
pub struct OLabelCompare {}
impl TrCompare for OLabelCompare {
fn compare<W: Semiring>(a: &Tr<W>, b: &Tr<W>) -> Ordering {
a.olabel.cmp(&b.olabel)
}
fn properties(inprops: FstProperties) -> FstProperties {
let mut outprops =
(inprops & FstProperties::arcsort_properties()) | FstProperties::O_LABEL_SORTED;
if inprops.contains(FstProperties::ACCEPTOR) {
outprops |= FstProperties::I_LABEL_SORTED;
}
outprops
}
}
pub fn tr_sort<W, F, C>(fst: &mut F, _comp: C)
where
W: Semiring,
F: MutableFst<W>,
C: TrCompare,
{
let props = fst.properties();
for state in 0..(fst.num_states() as StateId) {
fst.sort_trs_unchecked(state, C::compare);
}
fst.set_properties_with_mask(C::properties(props), FstProperties::all_properties());
}