dedent

A Rust procedural macro for stripping whitespace from multi-line string literals while preserving relative indentation.

Features

• 📐 Preserves relative indentation between lines
• 🧹 Trims leading and trailing empty lines

Usage

use dedent::dedent;

fn main() {
    // Basic usage
    let code = dedent!(r#"
        fn main() {
            println!("Hello, world!");
        }
    "#);
    
    println!("{}", code);
    // Output:
    // fn main() {
    //     println!("Hello, world!");
    // }

    // Works with varying indentation
    let text = dedent!(r#"
        First line
          Indented line
            More indented
        Back to start
    "#);
    
    println!("{}", text);
    // Output:
    // First line
    //   Indented line
    //     More indented
    // Back to start
}

How It Works

The dedent! macro:

1. Takes a string literal as input
2. Splits it into lines
3. Calculates the minimum indentation level across all non-empty lines
4. Removes that amount of whitespace from the start of each line
5. Removes leading and trailing empty lines
6. Preserves relative indentation between lines

License

Licensed under:

• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

Credits

This crate is inspired by the dedent npm package.