seq-macro

Crates.ioseq-macro
lib.rsseq-macro
version0.3.5
sourcesrc
created_at2018-08-22 21:18:19.293265
updated_at2023-07-15 19:24:46.191499
descriptionMacro to repeat sequentially indexed copies of a fragment of code.
homepage
repositoryhttps://github.com/dtolnay/seq-macro
max_upload_size
id80808
size44,570
Lanthanum (github:zxtn:lanthanum)

documentation

https://docs.rs/seq-macro

README

seq!

github crates.io docs.rs build status

A seq! macro to repeat a fragment of source code and substitute into each repetition a sequential numeric counter.

[dependencies]
seq-macro = "0.3"
use seq_macro::seq;

fn main() {
    let tuple = (1000, 100, 10);
    let mut sum = 0;

    // Expands to:
    //
    //     sum += tuple.0;
    //     sum += tuple.1;
    //     sum += tuple.2;
    //
    // This cannot be written using an ordinary for-loop because elements of
    // a tuple can only be accessed by their integer literal index, not by a
    // variable.
    seq!(N in 0..=2 {
        sum += tuple.N;
    });

    assert_eq!(sum, 1110);
}
  • If the input tokens contain a section surrounded by #( ... )* then only that part is repeated.

  • The numeric counter can be pasted onto the end of some prefix to form sequential identifiers.

use seq_macro::seq;

seq!(N in 64..=127 {
    #[derive(Debug)]
    enum Demo {
        // Expands to Variant64, Variant65, ...
        #(
            Variant~N,
        )*
    }
});

fn main() {
    assert_eq!("Variant99", format!("{:?}", Demo::Variant99));
}
  • Byte and character ranges are supported: b'a'..=b'z', 'a'..='z'.

  • If the range bounds are written in binary, octal, hex, or with zero padding, those features are preserved in any generated tokens.

use seq_macro::seq;

seq!(P in 0x000..=0x00F {
    // expands to structs Pin000, ..., Pin009, Pin00A, ..., Pin00F
    struct Pin~P;
});

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
Commit count: 153

cargo fmt