cargo-snippet

A snippet extractor for competitive programmers.

This allows you to manage your code snippets with tests and benchmarks available !!

Installing

You need to install rustfmt to run cargo-snippet.

$ rustup component add rustfmt

Install cargo-snippet

$ cargo install cargo-snippet --features="binaries"

Usage

Create a project for snippet.

$ cargo new --lib mysnippet

Add dependencies to Cargo.toml.

[dependencies]
cargo-snippet = "0.6"

Note: cargo-snippet on dependencies is needed just for register #[snippet] attribute to prevent the error from the compiler. All logics that extract snippet is in the binary package which is installed by Installing section.

Then write some snippet codes and tests.

use cargo_snippet::snippet;

// Annotate snippet name
#[snippet("mymath")]
#[snippet("gcd")]
fn gcd(a: u64, b: u64) -> u64 {
    if b == 0 {
        a
    } else {
        gcd(b, a % b)
    }
}

// Also works
#[snippet(name = "mymath")]
// Equivalent to #[snippet("lcm")]
#[snippet]
fn lcm(a: u64, b: u64) -> u64 {
    a / gcd(a, b) * b
}

#[snippet]
// Include snippet
#[snippet(include = "gcd")]
fn gcd_list(list: &[u64]) -> u64 {
    list.iter().fold(list[0], |a, &b| gcd(a, b))
}

// You can set prefix string.
// Note: All codes will be formatted by rustfmt on output
#[snippet(prefix = "use std::io::{self,Read};")]
#[snippet(prefix = "use std::str::FromStr;")]
fn foo() {}

// By default, doc comments associated with items will be output with the snippet.
#[snippet]
/// This is a document!
fn documented() {
    //! Inner document also works.
}

// If you want doc comment to be hidden, append `doc_hidden` keyword.
#[snippet(doc_hidden, prefix = "use std::collections::HashMap;")]
/// This is a doc comment for `bar`.
/// Since `doc_hidden` is specified, it won't be present in the snippet.
fn bar() {
    //! And this is also a doc comment for `bar`, which will be removed.
}

#[test]
fn test_gcd() {
    assert_eq!(gcd(57, 3), 3);
}

#[test]
fn test_lcm() {
    assert_eq!(lcm(3, 19), 57);
}

You can test as always:

$ cargo test

Extract snippet !

$ cargo snippet
snippet foo
    use std::io::{self, Read};
    use std::str::FromStr;
    fn foo() {}

snippet documented
    /// This is a document!
    fn documented() {
        //! Inner document also works.
    }

snippet bar
    use std::collections::HashMap;
    fn bar() {}

snippet gcd
    fn gcd(a: u64, b: u64) -> u64 {
        if b == 0 {
            a
        } else {
            gcd(b, a % b)
        }
    }

snippet gcd_list
    fn gcd(a: u64, b: u64) -> u64 {
        if b == 0 {
            a
        } else {
            gcd(b, a % b)
        }
    }
    fn gcd_list(list: &[u64]) -> u64 {
        list.iter().fold(list[0], |a, &b| gcd(a, b))
    }

snippet lcm
    fn lcm(a: u64, b: u64) -> u64 {
        a / gcd(a, b) * b
    }

snippet mymath
    fn gcd(a: u64, b: u64) -> u64 {
        if b == 0 {
            a
        } else {
            gcd(b, a % b)
        }
    }
    fn lcm(a: u64, b: u64) -> u64 {
        a / gcd(a, b) * b
    }

Example

My snippets here.

Supported output format

• Neosnippet
• VScode
• Ultisnips

You can specify output format via -t option. See cargo snippet -h.