rust project management

basic concepts

  • Packages: A Cargo feature that lets you build, test, and share crates
  • Crates: A tree of modules that produces a library or executable
  • Modules and use: Let you control the organization, scope, and privacy of paths
  • Paths: A way of naming an item, such as a struct, function, or module

package

  1. one package can only has one library Crate. default is src/lib.rs
  2. one package can have multiple binary Crates (under src/bin). default src/main.rs
  3. one package has at least one crate，no matter lib or bin。
  4. one package could simultaneously have src/main.rs and src/lib.rs (crate name same to package name)
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    cargo new my-project --lib  ## create a library project

crate

  • binary or library
  • The crate root is a source file that the Rust compiler starts from and makes up the root module of your crate

module

  • keyword mod
  • module could be nested。
  • module includes(struct、enum、const、trait、func, etc)

path

  • absolute path: use crate name or crate
  • relative path:，use self, super etc
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    fn serve_order() {}
    mod back_of_house {
        fn fix_incorrect_order() {
            cook_order();
            super::serve_order();
        }
        fn cook_order() {}
    }
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    mod front_of_house {
        pub mod hosting {
            pub fn add_to_waitlist() {}
        }
    }
    pub fn eat_at_restaurant() {
        // Absolute path
        crate::front_of_house::hosting::add_to_waitlist();
        // Relative path
        front_of_house::hosting::add_to_waitlist();
    }

Bringing Paths into Scope with the use Keyword

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use std::io;
use std::io::Write;
use std::io:: { self, Write} ;
use std::{cmp::Ordering, io};
use std::fmt::Result;
use std::io::Result as IoResult;
use std::collections::*;

pub use crate::front_of_house::hosting; // re-exporting names with pub use

Separating Modules into Different Files

Filename: src/lib.rs

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mod front_of_house;

pub use crate::front_of_house::hosting;

pub fn eat_at_restaurant() {
    hosting::add_to_waitlist();
    hosting::add_to_waitlist();
    hosting::add_to_waitlist();
}

Filename: src/front_of_house.rs

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pub mod hosting {
    pub fn add_to_waitlist() {}
}

profile

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cargo build ## dev: [unoptimized + debuginfo]
cargo build --release ## [optimized]
  • config
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    [profile.dev]
    opt-level = 0

    [profile.release]
    opt-level = 3

    # profile for the wasm example (from project ethers-rs)
    [profile.release.package.ethers-wasm]
    opt-level = "s"  # Tell `rustc` to optimize for small code size.