Add partial ratio

src/common.rs

@@ -1,3 +1,4 @@
+use crate::distance::common::ScoreAlignment;
 use std::fmt::Debug;
 
 #[derive(Default, Copy, Clone)]
@@ -50,16 +51,19 @@ where
     T: Copy,
 {
     type Output: Copy + Into<Option<T>> + PartialEq + Debug;
+    type AlignmentOutput: Copy + Into<Option<ScoreAlignment>> + PartialEq + Debug;
 
     fn cutoff(&self) -> Option<T>;
     fn score(&self, raw: T) -> Self::Output;
+    fn alignment(&self, raw: Option<ScoreAlignment>) -> Self::AlignmentOutput;
 }
 
 impl<T> SimilarityCutoff<T> for NoScoreCutoff
 where
     T: Copy + PartialEq + Debug,
 {
     type Output = T;
+    type AlignmentOutput = ScoreAlignment;
 
     fn cutoff(&self) -> Option<T> {
         None
@@ -68,13 +72,18 @@ where
     fn score(&self, raw: T) -> Self::Output {
         raw
     }
+
+    fn alignment(&self, raw: Option<ScoreAlignment>) -> Self::AlignmentOutput {
+        raw.unwrap()
+    }
 }
 
 impl<T> SimilarityCutoff<T> for WithScoreCutoff<T>
 where
     T: Copy + PartialOrd + Debug,
 {
     type Output = Option<T>;
+    type AlignmentOutput = Option<ScoreAlignment>;
 
     fn cutoff(&self) -> Option<T> {
         Some(self.0)
@@ -83,4 +92,8 @@ where
     fn score(&self, raw: T) -> Self::Output {
         (raw >= self.0).then_some(raw)
     }
+
+    fn alignment(&self, raw: Option<ScoreAlignment>) -> Self::AlignmentOutput {
+        raw
+    }
 }

src/distance.rs

@@ -1,3 +1,4 @@
+pub mod common;
 pub mod damerau_levenshtein;
 pub mod hamming;
 pub mod indel;

src/distance/common.rs

@@ -0,0 +1,15 @@
+/**
+Tuple like object describing the position of the compared strings in
+src and dest.
+
+It indicates that the score has been calculated between
+src[src_start:src_end] and dest[dest_start:dest_end]
+*/
+#[derive(PartialEq, Debug, Clone, Copy)]
+pub struct ScoreAlignment {
+    pub score: f64,
+    pub src_start: usize,
+    pub src_end: usize,
+    pub dest_start: usize,
+    pub dest_end: usize,
+}