Add operational transform example

Cargo.lock

@@ -352,6 +352,12 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3b5ca7a04898ad4bcd41c90c5285445ff5b791899bb1b0abdd2a2aa791211d7"
 
+[[package]]
+name = "bytecount"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2c676a478f63e9fa2dd5368a42f28bba0d6c560b775f38583c8bbaa7fcd67c9c"
+
 [[package]]
 name = "byteorder"
 version = "1.4.3"
@@ -1725,6 +1731,15 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "624a8340c38c1b80fd549087862da4ba43e08858af025b236e509b6649fc13d5"
 
+[[package]]
+name = "operational-transform"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fcdc542261d37288fd18ccb2eb1fdf333d8d10d12cce21d3f586d6e74a5511df"
+dependencies = [
+ "bytecount",
+]
+
 [[package]]
 name = "os_str_bytes"
 version = "6.3.1"
@@ -2258,6 +2273,7 @@ dependencies = [
  "notify",
  "num-bigint",
  "once_cell",
+ "operational-transform",
  "path-absolutize",
  "rayon",
  "regex",

Cargo.toml

@@ -29,6 +29,7 @@ log = { version = "0.4.17" }
 notify = { version = "4.0.17" }
 num-bigint = { version = "0.4.3" }
 once_cell = { version = "1.16.0" }
+operational-transform = "0.6.1"
 path-absolutize = { version = "3.0.14", features = ["once_cell_cache", "use_unix_paths_on_wasm"] }
 rayon = { version = "1.5.3" }
 regex = { version = "1.6.0" }

examples/crdt.rs

@@ -0,0 +1,25 @@
+use operational_transform::OperationSeq;
+
+pub fn main() {
+    let s = "Union[int, Option[str]]";
+    let mut a = OperationSeq::default();
+    a.delete("Union[".len() as u64);
+    a.retain("int".len() as u64);
+    a.delete(",".len() as u64);
+    a.insert(" |");
+    a.retain(" Option[str]".len() as u64);
+    a.delete("]".len() as u64);
+
+    let mut b = OperationSeq::default();
+    b.retain("Union[int, ".len() as u64);
+    b.delete("Option[".len() as u64);
+    b.retain("str".len() as u64);
+    b.insert(" | None");
+    b.delete("]".len() as u64);
+    b.retain("]".len() as u64);
+
+    let (_, b_prime) = a.transform(&b).unwrap();
+    let ab_prime = a.compose(&b_prime).unwrap();
+    let s = ab_prime.apply(s).unwrap();
+    println!("{}", s); // int | str | None
+}