Textwrap is a small Rust crate for word wrapping strings. You can use it to format strings for display in commandline applications.
Add this to your Cargo.toml:
toml
[dependencies]
textwrap = "0.3"
and this to your crate root:
rust
extern crate textwrap;
Word wrapping single strings is easy using the fill function:
```rust
extern crate textwrap;
use textwrap::fill;
fn main() {
let output = "textwrap: a small library for wrapping output.";
println!("{}", fill(output, 18));
}
The output is
textwrap: a small
library for
wrapping output.
```
You can use automatic hyphenation using TeX hyphenation patterns (with support for about 70 languages) and get: ```rust extern crate hyphenation; extern crate textwrap;
use hyphenation::Language; use textwrap::Wrapper;
fn main() { let corpus = hyphenation::load(Language::English_US).unwrap(); let mut wrapper = Wrapper::new(18); wrapper.corpus = Some(&corpus); let output = "textwrap: a small library for wrapping output."; println!("{}", wrapper.fill(output)) } ```
The output now looks like this:
textwrap: a small
library for wrap-
ping output.
Strings are wrapped based on their displayed width,
not their size in bytes. For ASCII characters such as a and !, the
displayed with is the same as the number of bytes used to UTF-8 encode
the character (one character takes up one byte). However, non-ASCII
characters and symbols take up more than one byte: é is 0xc3 0xa9
and ⚙ is 0xe2 0x9a 0x99 in UTF-8, respectively. This means that
relying solely on the string length in bytes would give incorrect
results.
The library comes with a small example program that shows how a fixed example string is wrapped at different widths. The string is
Memory safety without garbage collection. Concurrency without data races. Zero-cost abstractions.
When run, the string is wrapped at all widths between 15 and 60 columns:
```shell $ cargo run --example layout .--- Width: 15 ---. | Memory safety | | without garbage | | collection. | | Concurrency | | without data | | races. Zero- | | cost abstrac- | | tions. | .--- Width: 16 ----. | Memory safety | | without garbage | | collection. Con- | | currency without | | data races. Ze- | | ro-cost abstrac- | | tions. |
.-------------------- Width: 49 --------------------. | Memory safety without garbage collection. Concur- | | rency without data races. Zero-cost abstractions. | .---------------------- Width: 53 ----------------------. | Memory safety without garbage collection. Concurrency | | without data races. Zero-cost abstractions. | .------------------------- Width: 59 -------------------------. | Memory safety without garbage collection. Concurrency with- | | out data races. Zero-cost abstractions. | ```
Notice how words are split at hyphens (such a s "zero-cost") but also how words are hyphenated using automatic/machine hyphenation.
Version 0.2.0, December 28 2016: Introduced Wrapper struct.
Added support for wrapping on hyphens.
Version 0.1.0, December 17 2016: First public release with support for wrapping strings on whitespace.
Textwrap can be distributed according to the MIT license. Contributions will be accepted under the same license.