Rust

The Rust library is the lingara crate on crates.io. It needs Rust 1.87 or later and runs on the Tokio runtime. TLS comes from rustls by default, or from the platform’s own TLS through a feature.

How it reads

Every call is an async fn that returns a Result. To cancel a call, drop its future; to cancel a stream, drop the stream.
A stream arrives once the response headers do, as a Stream of results. Read it with .next().await.
Errors are one Error enum with four variants. Error::retry_after returns the wait the API named, when there was one.
Build a client with Client::builder(). To share a connection pool, hand it your own reqwest::Client, but give that client no total timeout, or it will cut long streams short. For a deadline on one call, wrap it in tokio::time::timeout.

The samples below install the crate, create a client, stream a vocabulary list and handle an error.

Rust

cargo add lingara@0.1.0-alpha.6
cargo add tokio --features macros,rt-multi-thread

Rust

use lingara::Client;

let client = Client::builder()
    .client_credentials(std::env::var("LINGARA_CLIENT_ID")?, std::env::var("LINGARA_CLIENT_SECRET")?)
    .build()?;

Rust

use lingara::models::{GenerateVocabularyEvent, VocabRequest};
use std::num::NonZeroU8;

let request = VocabRequest { level: 2, source_lang: "en".into(), target_lang: "zh".into(), count: NonZeroU8::new(8) };
let mut stream = client.generate_vocabulary(&request).await?;
while let Some(event) = stream.next().await {
    if let GenerateVocabularyEvent::Item(item) = event? {
        println!("{} {}", item.word, item.translation);
    }
}

Rust

use lingara::Error;

let result = client.get_usage().await;
if let Some(wait) = result.as_ref().err().and_then(Error::retry_after) {
    eprintln!("the API asks you to retry after {wait:?}");
}
match result {
    Ok(usage) => println!("{} allowance rows", usage.allowance.len()),
    // A refusal from the API: status, code (stable) and message (localised).
    Err(Error::Api(e)) => eprintln!("{} {} {}", e.status, e.code, e.message),
    // The token endpoint refused the credentials or the scopes.
    Err(Error::OAuth(e)) => eprintln!("{} {} {}", e.status, e.error, e.description.unwrap_or_default()),
    Err(Error::Maintenance(_)) => eprintln!("the API is under maintenance"),
    // No usable answer: connect, tls, reset, timeout, and so on.
    Err(Error::Transport(e)) => eprintln!("transport: {}", e.kind),
    Err(other) => return Err(other.into()),
}

Rust

How it reads

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