# indoc - Rust
github crates-io docs-rs
Keywords: rust, rustlang, rust-lang, indoc

# Crate indoc [−] [src]

This crate provides a procedural macro for indented string literals. The `indoc!()` macro takes a multiline string literal and un-indents it so the leftmost non-space character is in the first column.

    [dependencies]
    indoc = "0.3"

Release notes are available under GitHub releases.

# Using Indoc

    use indoc::indoc;

    fn main() {
        let testing = indoc!("
            def hello():
                print('Hello, world!')

            hello()
            ");
        let expected = "def hello():\n    print('Hello, world!')\n\nhello()\n";
        assert_eq!(testing, expected);
    }

Indoc also works with raw string literals:

    use indoc::indoc;

    fn main() {
        let testing = indoc!(r#"
            def hello():
                print("Hello, world!")

            hello()
            "#);
        let expected = "def hello():\n    print(\"Hello, world!\")\n\nhello()\n";
        assert_eq!(testing, expected);
    }

And byte string literals:

    use indoc::indoc;

    fn main() {
        let testing = indoc!(b"
            def hello():
                print('Hello, world!')

            hello()
            ");
        let expected = b"def hello():\n    print('Hello, world!')\n\nhello()\n";
        assert_eq!(testing[..], expected[..]);
    }

# Explanation

The following rules characterize the behavior of the `indoc!()` macro:

1. Count the leading spaces of each line, ignoring the first line and any lines that are empty or contain spaces only.
2. Take the minimum.
3. If the first line is empty i.e. the string begins with a newline, remove the first line.
4. Remove the computed number of spaces from the beginning of each line.

This means there are a few equivalent ways to format the same string, so choose one you like. All of the following result in the string `"line one\nline two\n"`:

    indoc!("            /      indoc!(             /      indoc!("line one
       line one        /         "line one        /               line two
       line two       /           line two       /                ")
       ")            /            ")            /

## Macros

indoc |