Useful Tidbits

Importing crates vs std lib

// for extenal dependencies extern crate clap; use clap::App; // for standard Rust libraries use std::fs;

Reading YAML

Note that this is being done by using the clap crate that is used for CLI tools - may need to update for appropraite use with rust-yaml:

#[macro_use] extern crate clap; use clap::App; fn main() { let yaml = load_yaml!("cli.yml"); println!("{:#?}", yaml); }

Reading JSON

#[macro_use] extern crate serde_json; use std::path::Path; use std::fs::File; fn main() { let json_file_path = Path::new("src/test.json"); let json_file = File::open(json_file_path).expect("file not found"); let json: serde_json::Value = serde_json::from_reader(json_file).expect("JSON was not well-formatted"); println!("{:#?}", json); }


Object( { "id": String( "1234" ), "object": Object( { "array": Array( [ Number( 1 ), Number( 2 ), Number( 3 ) ] ) } ) } )


You want to implement the Debug trait on your struct. Using #[derive(Debug)] is the easiest solution. Then you can print it with {:?}:

#[derive(Debug)] struct MyStruct{ a: i32, b: i32 } fn main() { let x = MyStruct{ a: 10, b: 20 }; println!("{:?}", x); }

In use:

// assuming matches is a struct or array println!("{:?}", matches); // logging out structs or arrays println!("{:#?}", matches); // pretty print println!("{}", matches.occurrences_of("verbose"));