You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: hello.rs
    path of file: ./repos/glicol/rs/main/examples
    
    the code of the file until where you have to start completion: use glicol::Engine;
// use glicol::{EngineError, get_error_info};

// use glicol::GlicolNodeInfo;
// use std::collections::HashMap;

fn main() {
    let mut engine = Engine::<32>::new();
    engine.update_with_code(r#"o: constsig 1.0 >> pan 0.9"#);
    // engine.update_with_code(r#"o: [0.1=>100, 1/2=> 1.0]"#);
    // engine.update_with_code(r#"o: sin 440"#);
    // engine.update_with_code(r#"// a sawtooth osc chained with a onepole filter
    // // the first meta is to write a saw manually
    // out: meta `
    //     f = 220.;
    //     output.pad(128, 0.0);
    //     for i in 0..128 {
    //         output[i] = p * 2. - 1.;
    //         p += f / sr;
    //     };
    //     if p >
    
fn main() {
    let mut engine = Engine::<32>::new();
    engine.update_with_code(r#"o: constsig 1.0 >> pan 0.9"#);
    // engine.update_with_code(r#"o: [0.1=>100, 1/2=> 1.0]"#);
    // engine.update_with_code(r#"o: sin 440"#);
    // engine.update_with_code(r#"// a sawtooth osc chained with a onepole filter
    // // the first meta is to write a saw manually
    // out: meta `
    //     f = 220.;
    //     output.pad(128, 0.0);
    //     for i in 0..128 {
    //         output[i] = p * 2. - 1.;
    //         p += f / sr;
    //     };
    //     if p > 1.0 { p -= 1.0 };
    //     output
    // ` >> meta `
    //     r = 1./2000.;
    //     if phase == 0.0 {
    //         z = 0.0
    //     }
    //     output.pad(128, 0.0);
    //     b = (-2.0 * PI() * r).exp();
    //     a = 1.0 - b;
    //     for i in 0..128 {
    //         y = input[i] * a + b * z;
    //         output[i] = y;
    //         z = y;
    //     };
    //     output
    // `
    // // if the script has an input, you can use the "input" variable
    // // the "input" is a 128-size array in web audio"#);
    // match engine.update("o: imp 100 >> mul ~mod
    // ~mo: sin 1 >> mul 0.5 >> add 0.5") {
    //     Ok(_) => {},
    //     Err(e) => {
    //         println!("{:?}", e);
    //         // match e {
    //         //     EngineError::ParsingError(e) => {
    //         //         println!("{:?}", get_error_info(e))
    //         //     },
    //         //     _ => unimplemented!()
    //         // }
    //     }
    // };
    // println!("refpairlist {:?}", engine.refpairlist);
    // engine.update("o: saw 500 >> lpf 100.0 1.0;

    // ~mod: sin 0.2 >> mul 200.0 >> add 500.0");
    // engine.add_sample("\\bb", &[1.0], 1);
    // engine.update(r#"o: imp 1 >> sp \808_0 >> delayms ~mod

    // ~mod: sin 0.2 >> mul 100 >> add 200"#);
    // for e in engine.context.graph.edges(engine.context.destination) {
    //     println!("destinations {:?}", e);
    // }
    println!("next block {:?}", engine.next_block(vec![]));
    // engine.send_msg("o", 0, (0, "1."));
    // engine.next_block();
}