use std::borrow::Borrow;
use std::f32;
use std::hash::{Hash, Hasher};
use std::io::Write;
use anyhow::Result;
use nom::number::complete::float;
use nom::IResult;
use ordered_float::OrderedFloat;
use crate::parsers::nom_utils::NomCustomError;
use crate::parsers::parse_bin_f32;
use crate::parsers::write_bin_f32;
use crate::semirings::semiring::SerializableSemiring;
use crate::semirings::utils_float::float_approx_equal;
use crate::semirings::{
CompleteSemiring, DivideType, ReverseBack, Semiring, SemiringProperties, StarSemiring,
WeaklyDivisibleSemiring, WeightQuantize,
};
use crate::KDELTA;
#[derive(Clone, Debug, PartialOrd, Default, Copy, Eq)]
pub struct TropicalWeight {
value: OrderedFloat<f32>,
}
impl Semiring for TropicalWeight {
type Type = f32;
type ReverseWeight = TropicalWeight;
fn zero() -> Self {
Self {
value: OrderedFloat(f32::INFINITY),
}
}
fn one() -> Self {
Self {
value: OrderedFloat(0.0),
}
}
fn new(value: <Self as Semiring>::Type) -> Self {
TropicalWeight {
value: OrderedFloat(value),
}
}
fn plus_assign<P: Borrow<Self>>(&mut self, rhs: P) -> Result<()> {
if rhs.borrow().value < self.value {
self.value = rhs.borrow().value;
}
Ok(())
}
fn times_assign<P: Borrow<Self>>(&mut self, rhs: P) -> Result<()> {
let f1 = self.value();
let f2 = rhs.borrow().value();
if f1.eq(&f32::INFINITY) {
} else if f2.eq(&f32::INFINITY) {
self.value.0 = *f2;
} else {
self.value.0 += f2;
}
Ok(())
}
fn approx_equal<P: Borrow<Self>>(&self, rhs: P, delta: f32) -> bool {
float_approx_equal(self.value.0, rhs.borrow().value.0, delta)
}
fn value(&self) -> &Self::Type {
&self.value.0
}
fn take_value(self) -> Self::Type {
self.value.0
}
fn set_value(&mut self, value: <Self as Semiring>::Type) {
self.value.0 = value
}
fn reverse(&self) -> Result<Self::ReverseWeight> {
Ok(*self)
}
fn properties() -> SemiringProperties {
SemiringProperties::LEFT_SEMIRING
| SemiringProperties::RIGHT_SEMIRING
| SemiringProperties::COMMUTATIVE
| SemiringProperties::PATH
| SemiringProperties::IDEMPOTENT
}
}
impl ReverseBack<TropicalWeight> for TropicalWeight {
fn reverse_back(&self) -> Result<TropicalWeight> {
Ok(*self)
}
}
impl AsRef<TropicalWeight> for TropicalWeight {
fn as_ref(&self) -> &TropicalWeight {
self
}
}
display_semiring!(TropicalWeight);
impl CompleteSemiring for TropicalWeight {}
impl StarSemiring for TropicalWeight {
fn closure(&self) -> Self {
if self.value.is_sign_positive() && self.value.is_finite() {
Self::new(0.0)
} else {
Self::new(f32::NEG_INFINITY)
}
}
}
impl WeaklyDivisibleSemiring for TropicalWeight {
fn divide_assign(&mut self, rhs: &Self, _divide_type: DivideType) -> Result<()> {
self.value.0 -= rhs.value.0;
Ok(())
}
}
impl_quantize_f32!(TropicalWeight);
partial_eq_and_hash_f32!(TropicalWeight);
impl SerializableSemiring for TropicalWeight {
fn weight_type() -> String {
"tropical".to_string()
}
fn parse_binary(i: &[u8]) -> IResult<&[u8], Self, NomCustomError<&[u8]>> {
let (i, weight) = parse_bin_f32(i)?;
Ok((i, Self::new(weight)))
}
fn write_binary<F: Write>(&self, file: &mut F) -> Result<()> {
write_bin_f32(file, *self.value())
}
fn parse_text(i: &str) -> IResult<&str, Self> {
let (i, f) = float(i)?;
Ok((i, Self::new(f)))
}
}
test_semiring_serializable!(
tests_tropical_weight_serializable,
TropicalWeight,
TropicalWeight::one() TropicalWeight::zero() TropicalWeight::new(0.3) TropicalWeight::new(0.5) TropicalWeight::new(0.0) TropicalWeight::new(-1.2)
);
impl From<f32> for TropicalWeight {
fn from(f: f32) -> Self {
Self::new(f)
}
}