feat(sdk): add Lance backend struct + endpoint helper (companion to #35)

surrealdb/src/engine/any/native.rs

@@ -86,6 +86,27 @@ impl conn::Sealed for Any {
 				));
 				}
 
+				EndpointKind::Lance => {
+					#[cfg(feature = "kv-lance")]
+					{
+						features.insert(ExtraFeatures::Backup);
+						features.insert(ExtraFeatures::LiveQueries);
+						tokio::spawn(engine::local::native::run_router(
+							address,
+							conn_tx,
+							route_rx,
+							session_clone.receiver.clone(),
+						));
+						conn_rx.recv().await.map_err(crate::std_error_to_types_error)??
+					}
+
+					#[cfg(not(feature = "kv-lance"))]
+				return Err(Error::configuration(
+					"Cannot connect to the `lance` storage engine as it is not enabled in this build of SurrealDB".to_string(),
+					None,
+				));
+				}
+
 				EndpointKind::TiKv => {
 					#[cfg(feature = "kv-tikv")]
 					{

surrealdb/src/engine/any/wasm.rs

@@ -92,6 +92,23 @@ impl conn::Sealed for Any {
 			return Err(Error::internal("Cannot connect to the `rocksdb` storage engine as it is not enabled in this build of SurrealDB".to_owned()));
 				}
 
+				EndpointKind::Lance => {
+					#[cfg(feature = "kv-lance")]
+					{
+						features.insert(ExtraFeatures::LiveQueries);
+						spawn_local(engine::local::wasm::run_router(
+							address,
+							conn_tx,
+							route_rx,
+							session_clone.receiver.clone(),
+						));
+						conn_rx.recv().await.map_err(crate::std_error_to_types_error)??;
+					}
+
+					#[cfg(not(feature = "kv-lance"))]
+			return Err(Error::internal("Cannot connect to the `lance` storage engine as it is not enabled in this build of SurrealDB".to_owned()));
+				}
+
 				EndpointKind::SurrealKv => {
 					#[cfg(feature = "kv-surrealkv")]
 					{

surrealdb/src/engine/local/mod.rs

@@ -287,6 +287,47 @@ pub struct Mem;
 #[derive(Debug)]
 pub struct RocksDb;
 
+/// Lance columnar database
+///
+/// Provides a Lance-backed local storage engine. Lance is a columnar dataset
+/// format with built-in vector search, manifest-based versioning, and
+/// append-only fragment storage. The Lance backend uses the path argument as
+/// the dataset location on the local filesystem.
+///
+/// # Examples
+///
+/// Instantiating a Lance-backed instance
+///
+/// ```no_run
+/// # #[tokio::main]
+/// # async fn main() -> surrealdb::Result<()> {
+/// use surrealdb::Surreal;
+/// use surrealdb::engine::local::Lance;
+///
+/// let db = Surreal::new::<Lance>("path/to/lance/dataset").await?;
+/// # Ok(())
+/// # }
+/// ```
+///
+/// Instantiating a Lance-backed strict instance
+///
+/// ```no_run
+/// # #[tokio::main]
+/// # async fn main() -> surrealdb::Result<()> {
+/// use surrealdb::opt::Config;
+/// use surrealdb::Surreal;
+/// use surrealdb::engine::local::Lance;
+///
+/// let config = Config::default().strict();
+/// let db = Surreal::new::<Lance>(("path/to/lance/dataset", config)).await?;
+/// # Ok(())
+/// # }
+/// ```
+#[cfg(feature = "kv-lance")]
+#[cfg_attr(docsrs, doc(cfg(feature = "kv-lance")))]
+#[derive(Debug)]
+pub struct Lance;
+
 /// IndxDB database
 ///
 /// # Examples

surrealdb/src/opt/endpoint/lance.rs

@@ -0,0 +1,41 @@
+use std::path::{Path, PathBuf};
+
+use url::Url;
+
+use crate::Result;
+use crate::engine::local::{Db, Lance};
+use crate::opt::endpoint::into_endpoint;
+use crate::opt::{Config, Endpoint, IntoEndpoint};
+
+macro_rules! endpoints {
+	($($name:ty),*) => {
+		$(
+			impl IntoEndpoint<Lance> for $name {}
+			impl into_endpoint::Sealed<Lance> for $name {
+				type Client = Db;
+
+				fn into_endpoint(self) -> Result<Endpoint> {
+					let protocol = "lance://";
+					let url = Url::parse(protocol)
+					    .unwrap_or_else(|_| unreachable!("`{protocol}` should be static and valid"));
+					let mut endpoint = Endpoint::new(url);
+					endpoint.path = super::path_to_string(protocol, self);
+					Ok(endpoint)
+				}
+			}
+
+			impl IntoEndpoint<Lance> for ($name, Config) {}
+			impl into_endpoint::Sealed<Lance> for ($name, Config) {
+				type Client = Db;
+
+				fn into_endpoint(self) -> Result<Endpoint> {
+					let mut endpoint = into_endpoint::Sealed::<Lance>::into_endpoint(self.0)?;
+					endpoint.config = self.1;
+					Ok(endpoint)
+				}
+			}
+		)*
+	}
+}
+
+endpoints!(&str, &String, String, &Path, PathBuf);

surrealdb/src/opt/endpoint/mod.rs

@@ -9,12 +9,14 @@ mod indxdb;
 mod mem;
 #[cfg(feature = "kv-rocksdb")]
 mod rocksdb;
+#[cfg(feature = "kv-lance")]
+mod lance;
 #[cfg(feature = "kv-surrealkv")]
 mod surrealkv;
 #[cfg(feature = "kv-tikv")]
 mod tikv;
 
-#[cfg(any(feature = "kv-mem", feature = "kv-surrealkv", feature = "kv-rocksdb"))]
+#[cfg(any(feature = "kv-mem", feature = "kv-surrealkv", feature = "kv-rocksdb", feature = "kv-lance"))]
 mod local;
 
 use url::Url;
@@ -54,7 +56,7 @@ impl Endpoint {
 	/// Append a query parameter to the endpoint path string.
 	/// Only used when a local engine (e.g. `kv-mem`, `kv-rocksdb`) is enabled.
 	#[cfg_attr(
-		not(any(feature = "kv-mem", feature = "kv-surrealkv", feature = "kv-rocksdb")),
+		not(any(feature = "kv-mem", feature = "kv-surrealkv", feature = "kv-rocksdb", feature = "kv-lance")),
 		allow(dead_code)
 	)]
 	pub(crate) fn append_query_param(&mut self, key: &str, value: &str) {
@@ -151,6 +153,7 @@ pub enum EndpointKind {
 	IndxDb,
 	Memory,
 	RocksDb,
+	Lance,
 	TiKv,
 	Unsupported(String),
 	SurrealKv,
@@ -167,6 +170,7 @@ impl From<&str> for EndpointKind {
 			"indxdb" => Self::IndxDb,
 			"mem" => Self::Memory,
 			"rocksdb" => Self::RocksDb,
+			"lance" => Self::Lance,
 			"tikv" => Self::TiKv,
 			"surrealkv" => Self::SurrealKv,
 			_ => Self::Unsupported(s.to_owned()),