rustfst/algorithms/factor_weight/factor_iterators/
string_factor.rs

1use crate::algorithms::factor_weight::FactorIterator;
2use crate::semirings::{
3    StringWeightLeft, StringWeightRestrict, StringWeightRight, StringWeightVariant,
4};
5
6#[derive(Debug, PartialEq, Clone)]
7/// Factors a StringWeightLeft w as 'ab' where 'a' is a label.
8pub struct StringFactorLeft {
9    weight: StringWeightLeft,
10    done: bool,
11}
12
13#[derive(Debug, PartialEq, Clone)]
14/// Factors a StringFactorRight w as 'ab' where 'a' is a label.
15pub struct StringFactorRight {
16    weight: StringWeightRight,
17    done: bool,
18}
19
20#[derive(Debug, PartialEq, Clone)]
21/// Factors a StringFactorRestrict w as 'ab' where 'a' is a label.
22pub struct StringFactorRestrict {
23    weight: StringWeightRestrict,
24    done: bool,
25}
26
27macro_rules! impl_string_factor {
28    ($factor: ident, $semiring: ident) => {
29        impl Iterator for $factor {
30            type Item = ($semiring, $semiring);
31
32            fn next(&mut self) -> Option<Self::Item> {
33                if self.done() {
34                    return None;
35                }
36                let l = self.weight.value.unwrap_labels();
37                let l1 = vec![l[0]];
38                let l2: Vec<_> = l.iter().skip(1).cloned().collect();
39                self.done = true;
40                Some((l1.into(), l2.into()))
41            }
42        }
43
44        impl FactorIterator<$semiring> for $factor {
45            fn new(weight: $semiring) -> Self {
46                let done = match &weight.value {
47                    StringWeightVariant::Infinity => true,
48                    StringWeightVariant::Labels(l) => (l.len() == 0),
49                };
50                Self { weight, done }
51            }
52            fn done(&self) -> bool {
53                self.done
54            }
55        }
56    };
57}
58
59impl_string_factor!(StringFactorLeft, StringWeightLeft);
60impl_string_factor!(StringFactorRight, StringWeightRight);
61impl_string_factor!(StringFactorRestrict, StringWeightRestrict);
rustfst/algorithms/factor_weight/factor_iterators/string_factor.rs

rustfst/algorithms/factor_weight/factor_iterators/
string_factor.rs
