syncmer docs

Author: RagnarGrootKoerkamp

README.md

@@ -57,6 +57,14 @@ let minimizer_vals: Vec<u64> = canonical_minimizers(k, w)
     .run(packed_seq.as_slice(), &mut minimizer_positions)
     .values_u64()
     .collect();
+    
+// Compute _syncmers_ positions and values instead:
+let mut syncmer_positions = Vec::new();
+// List of (k+w-1)-mer values.
+let syncmer_vals: Vec<u64> = canonical_syncmers(k, w)
+    .run(packed_seq.as_slice(), &mut syncmer_positions)
+    .values_u64()
+    .collect();
 ```
 
 ## Benchmarks

src/lib.rs

@@ -44,6 +44,14 @@
 //! 3. Compute the 'preferred' strand of the current window as the one with more `TG` characters. This requires `l=w+k-1` to be odd for proper tie-breaking.
 //! 4. Return either the leftmost or rightmost smallest k-mer, depending on the preferred strand.
 //!
+//! ## Syncmers
+//!
+//! _Syncmers_ are (in our notation) windows of length `l = w + k - 1` characters where the minimizer k-mer is a prefix or suffix.
+//! (Or, in classical notation, `k`-mers with the smallest `s`-mer as prefix or suffix.)
+//! These can be computed by using [`syncmers`] or [`canonical_syncmers`] instead of [`minimizers`] or [`canonical_minimizers`].
+//!
+//! Note that canonical syncmers are chosen as the minimum of the forward and reverse-complement k-mer representation.
+//!
 //! ## Input types
 //!
 //! This crate depends on [`packed-seq`] to handle generic types of input sequences.