[go: up one dir, main page]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125

// Copyright 2016 Indoc Developers
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! 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.
//!
//! ```toml
//! [dependencies]
//! indoc = "0.3"
//! ```
//!
//! Release notes are available under [GitHub releases](https://github.com/dtolnay/indoc/releases).
//!
//! # Using Indoc
//!
//! ```rust
#![cfg_attr(
    feature = "unstable",
    doc = " #![feature(proc_macro_hygiene)]"
)]
#![cfg_attr(feature = "unstable", doc = "")]
//! extern crate 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:
//!
//! ```rust
#![cfg_attr(
    feature = "unstable",
    doc = " #![feature(proc_macro_hygiene)]"
)]
#![cfg_attr(feature = "unstable", doc = "")]
//! extern crate indoc;
//! 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
#![cfg_attr(
    feature = "unstable",
    doc = " #![feature(proc_macro_hygiene)]"
)]
#![cfg_attr(feature = "unstable", doc = "")]
//! extern crate indoc;
//! 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"`:
//!
//! ```text
//! indoc!("            /      indoc!(             /      indoc!("line one
//!    line one        /         "line one        /               line two
//!    line two       /           line two       /                ")
//!    ")            /            ")            /
//! ```

#![doc(html_root_url = "https://docs.rs/indoc/0.3.0")]
#![cfg_attr(feature = "unstable", feature(decl_macro))]
#![cfg_attr(feature = "cargo-clippy", allow(useless_attribute))]
#![no_std]

#[cfg(not(feature = "unstable"))]
extern crate proc_macro_hack;

extern crate indoc_impl;

#[cfg(not(feature = "unstable"))]
use proc_macro_hack::proc_macro_hack;

#[cfg_attr(not(feature = "unstable"), proc_macro_hack)]
pub use indoc_impl::indoc;