Function rustfst::algorithms::compose

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>,

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);