Add table of benchmark results

README.md

@@ -11,6 +11,42 @@ crate. This crate uses less static storage, and is able to classify both ASCII
 and non-ASCII codepoints with better performance, 2–10× faster than
 `unicode-xid`.
 
+<br>
+
+## Comparison of performance
+
+The following table shows a comparison between five Unicode identifier
+implementations.
+
+- `unicode-ident` is this crate;
+- [`unicode-xid`] is a widely used crate run by the "unicode-rs" org;
+- `ucd-trie` and `fst` are two data structures supported by the [`ucd-generate`] tool;
+- [`roaring`] is a Rust implementation of Roaring bitmap.
+
+The *static storage* column shows the total size of `static` tables that the
+crate bakes into your binary, measured in 1000s of bytes.
+
+The remaining columns show the **cost per call** to evaluate whether a single
+`char` has the XID\_Start or XID\_Continue Unicode property, comparing across
+different ratios of ASCII to non-ASCII codepoints in the input data.
+
+[`unicode-xid`]: https://github.com/unicode-rs/unicode-xid
+[`ucd-generate`]: https://github.com/BurntSushi/ucd-generate
+[`roaring`]: https://github.com/RoaringBitmap/roaring-rs
+
+| | static storage | 0% nonascii | 1% | 10% | 100% nonascii |
+|---|---|---|---|---|---|
+| **`unicode-ident`** | 9.75 K | 0.96 ns | 0.95 ns | 1.09 ns | 1.55 ns |
+| **`unicode-xid`** | 11.34 K | 1.88 ns | 2.14 ns | 3.48 ns | 15.63 ns |
+| **`ucd-trie`** | 9.95 K | 1.29 ns | 1.28 ns | 1.36 ns | 2.15 ns |
+| **`fst`** | 133 K | 55.1 ns | 54.9 ns | 53.2 ns | 28.5 ns |
+| **`roaring`** | 66.1 K | 2.78 ns | 3.09 ns | 3.37 ns | 4.70 ns |
+
+Source code for the benchmark is provided in the *bench* directory of this repo
+and may be repeated by running `cargo criterion`.
+
+<br>
+
 ## License
 
 <sup>