Function rustfst::algorithms::compose
source · pub fn compose<W, F1, F2, F3>(fst_1: &F1, fst_2: &F2) -> Result<F3, Error>where
W: Semiring,
F1: ExpandedFst<W = W>,
F2: ExpandedFst<W = W>,
F3: MutableFst<W = W>,
Expand description
This operation computes the composition of two transducers.
If A
transduces string x
to y
with weight a
and B
transduces y
to z
with weight b
, then their composition transduces string x
to z
with weight a ⊗ b
.
Example
use rustfst::utils::transducer;
use rustfst::semirings::{Semiring, IntegerWeight};
use rustfst::fst_impls::VectorFst;
use rustfst::algorithms::compose;
let fst_1 : VectorFst<IntegerWeight> = transducer(
vec![1, 2].into_iter(),
vec![2, 3].into_iter()
).unwrap();
let fst_2 : VectorFst<IntegerWeight> = transducer(
vec![2, 3].into_iter(),
vec![3, 4].into_iter()
).unwrap();
let fst_ref : VectorFst<IntegerWeight> = transducer(
vec![1, 2].into_iter(),
vec![3, 4].into_iter()
).unwrap();
let composed_fst : VectorFst<_> = compose(&fst_1, &fst_2).unwrap();
assert_eq!(composed_fst, fst_ref);