Indented document literals for Rust
This crate provides a procedural macro for indented string literals. Theindoc!()
macro takes a multiline string literal and un-indents it at compile
time so the leftmost non-space character is in the first column.
[dependencies]
indoc = "2"
Compiler requirement: rustc 1.56 or greater.
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[..]);
}
The indoc crate exports five 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), ...)
concatdoc!(...)
— equivalent to concat!(...)
with each string literal wrapped in indoc!
use indoc::{concatdoc, printdoc};
const HELP: &str = concatdoc! {"
Usage: ", env!("CARGO_BIN_NAME"), " [options]
Options:
-h, --help
"};
fn main() {
printdoc! {"
GET {url}
Accept: {mime}
",
url = "http://localhost:8080",
mime = "application/json",
}
}
The following rules characterize the behavior of the indoc!()
macro:
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<u8>
use unindent::unindent;
fn main() {
let indented = "
line one
line two";
assert_eq!("line one\nline two", unindent(indented));
}
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.