Rust

Install via cargo:

cargo add perspective

Example

Initialize a server and client

#![allow(unused)]
fn main() {
let server = Server::default();
let client = server.new_local_client();
}

Load an Arrow

#![allow(unused)]
fn main() {
let mut file = File::open(std::path::Path::new(ROOT_PATH).join(ARROW_FILE_PATH))?;
let mut feather = Vec::with_capacity(file.metadata()?.len() as usize);
file.read_to_end(&mut feather)?;
let data = UpdateData::Arrow(feather.into());
let mut options = TableInitOptions::default();
options.set_name("my_data_source");
client.table(data.into(), options).await?;
}

Joining Tables

Client::join creates a read-only Table by joining two source tables on a shared key column. The result is reactive — it updates automatically when either source table changes. See Join for conceptual details.

#![allow(unused)]
fn main() {
let orders = client.table(
 TableData::Update(UpdateData::JsonRows(
 "[{\"id\":1,\"product_id\":101,\"qty\":5},{\"id\":2,\"product_id\":102,\"qty\":3}]".into(),
 )),
 TableInitOptions::default(),
).await?;
let products = client.table(
 TableData::Update(UpdateData::JsonRows(
 "[{\"product_id\":101,\"name\":\"Widget\"},{\"product_id\":102,\"name\":\"Gadget\"}]".into(),
 )),
 TableInitOptions::default(),
).await?;
let joined = client.join(
 (&orders).into(),
 (&products).into(),
 "product_id",
 JoinOptions::default(),
).await?;
let view = joined.view(None).await?;
let json = view.to_json().await?;
}

Use JoinOptions to configure the join type, table name, or right_on column:

#![allow(unused)]
fn main() {
let options = JoinOptions {
 join_type: Some(JoinType::Left),
 name: Some("orders_with_products".into()),
 right_on: None,
};
let joined = client.join(
 (&orders).into(),
 (&products).into(),
 "product_id",
 options,
).await?;
}

You can also join by table name strings instead of Table references:

#![allow(unused)]
fn main() {
let joined = client.join(
 "orders".into(),
 "products".into(),
 "product_id",
 JoinOptions::default(),
).await?;
}