Indented Documents (indoc) ========================== [github](https://github.com/dtolnay/indoc) [crates.io](https://crates.io/crates/indoc) [docs.rs](https://docs.rs/indoc) [build status](https://github.com/dtolnay/indoc/actions?query=branch%3Amaster) This crate provides a procedural macro for indented string literals. The `indoc!()` macro takes a multiline string literal and un-indents it at compile time so the leftmost non-space character is in the first column. ```toml [dependencies] indoc = "1.0" ``` *Compiler requirement: rustc 1.42 or greater.*
## Using indoc ```rust 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: ```rust 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: ```rust 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[..]); } ```
## Formatting macros The indoc crate exports four additional macros to substitute conveniently for the standard library's formatting macros: - `formatdoc!($fmt, ...)` — equivalent to `format!(indoc!($fmt), ...)` - `printdoc!($fmt, ...)` — equivalent to `print!(indoc!($fmt), ...)` - `eprintdoc!($fmt, ...)` — equivalent to `eprint!(indoc!($fmt), ...)` - `writedoc!($dest, $fmt, ...)` — equivalent to `write!($dest, indoc!($fmt), ...)` ```rust use indoc::printdoc; fn main() { printdoc! {" GET {url} Accept: {mime} ", url = "http://localhost:8080", mime = "application/json", } } ```
## 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.
## Unindent Indoc's indentation logic is available in the `unindent` crate. This may be useful for processing strings that are not statically known at compile time. The crate exposes two functions: - `unindent(&str) -> String` - `unindent_bytes(&[u8]) -> Vec` ```rust use unindent::unindent; fn main() { let indented = " line one line two"; assert_eq!("line one\nline two", unindent(indented)); } ```
#### 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.