Rust anatomy

This page is a general getting started in rust.

Filesystem

my_project/
  src/
    my_submodule/
      mod.rs            # my_submodule's code
      foobar.rs         # my_submodule::foobar's code
    main.rs             # executable entrypoint && tests
    lib.rs              # library entrypoint && tests
  tests/
    *.rs                # integration tests
  Cargo.toml
  Cargo.lock

Examples

Commandline Executable

TODO

Project Components

A rust project comprises of

workspaces	(optional) a set of packages sharing a Cargo.toml
packages	build/test/share a collection of crates
crates	tree of modules that build a single library, or executable
modules	organize scope/privacy of paths
paths	rust files

Packages

A package is a collection of crates.

• it may have multiple executable crates
• it may only have one library crate

myproject/
  src/
  Cargo.toml
  Cargo.lock

Cargo.toml

[package]
name = "my_project"
version = "0.1.0"
authors = ["Your Name <you@example.com>"]
edition = "2018"

[dependencies]
time = "0.1.12"
regex = "0.1.41"

cargo new my_project  # generate a new project

Crates

A crate is a build target for rust.
It can be either a library or an executable.

If a package only has a single library/executable, the crate type can be implied from the source files.

src/lib.rs   # if this exists, crate is a library
src/main.rs  # if this exists, crate is an executable

You can also specify multiple crates for your package in Cargo.toml.

# Cargo.toml

[package]
# ...

[[bin]]
name = "foo"  # refers to src/bin/foo.rs

[[bin]]
name = "bar"  # refers to src/bin/bar.rs

[lib]  # <-- single '['s
# refers to 'src/lib.rs', unless 'path' overrides it

Modules

Modules contain groups of related srcfiles.
modules are private to their parents by default, and public to their child modules.
the name/namespace of the module mirrors it's filesystem location.
the use keyword can merge a module or one of it's elements into the current namespace.

See more details in rust modules.