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//! `textwrap` provides functions for word wrapping and filling text.
//!
//! Wrapping text can be very useful in commandline programs where you
//! want to format dynamic output nicely so it looks good in a
//! terminal. A quick example:
//!
//! ```no_run
//! extern crate textwrap;
//! use textwrap::fill;
//!
//! fn main() {
//! let text = "textwrap: a small library for wrapping text.";
//! println!("{}", fill(text, 18));
//! }
//! ```
//!
//! This will display the following output:
//!
//! ```text
//! textwrap: a small
//! library for
//! wrapping text.
//! ```
//!
//! # Displayed Width vs Byte Size
//!
//! To word wrap text, one must know the width of each word so one can
//! know when to break lines. This library measures the width of text
//! using the [displayed width][unicode-width], not the size in bytes.
//!
//! This is important for non-ASCII text. ASCII characters such as `a`
//! and `!` are simple and take up one column each. This means that
//! the displayed width is equal to the string length in bytes.
//! However, non-ASCII characters and symbols take up more than one
//! byte when UTF-8 encoded: `é` is `0xc3 0xa9` (two bytes) and `⚙` is
//! `0xe2 0x9a 0x99` (three bytes) in UTF-8, respectively.
//!
//! This is why we take care to use the displayed width instead of the
//! byte count when computing line lengths. All functions in this
//! library handle Unicode characters like this.
//!
//! [unicode-width]: https://docs.rs/unicode-width/
#![doc(html_root_url = "https://docs.rs/textwrap/0.11.0")]
#![deny(missing_docs)]
#![deny(missing_debug_implementations)]
#[cfg(feature = "hyphenation")]
extern crate hyphenation;
#[cfg(feature = "term_size")]
extern crate term_size;
extern crate unicode_width;
use std::borrow::Cow;
use std::str::CharIndices;
use unicode_width::UnicodeWidthChar;
use unicode_width::UnicodeWidthStr;
/// A non-breaking space.
const NBSP: char = '\u{a0}';
mod indentation;
pub use indentation::dedent;
pub use indentation::indent;
mod splitting;
pub use splitting::{HyphenSplitter, NoHyphenation, WordSplitter};
/// A Wrapper holds settings for wrapping and filling text. Use it
/// when the convenience [`wrap_iter`], [`wrap`] and [`fill`] functions
/// are not flexible enough.
///
/// [`wrap_iter`]: fn.wrap_iter.html
/// [`wrap`]: fn.wrap.html
/// [`fill`]: fn.fill.html
///
/// The algorithm used by the `WrapIter` iterator (returned from the
/// `wrap_iter` method) works by doing successive partial scans over
/// words in the input string (where each single scan yields a single
/// line) so that the overall time and memory complexity is O(*n*) where
/// *n* is the length of the input string.
#[derive(Clone, Debug)]
pub struct Wrapper<'a, S: WordSplitter> {
/// The width in columns at which the text will be wrapped.
pub width: usize,
/// Indentation used for the first line of output.
pub initial_indent: &'a str,
/// Indentation used for subsequent lines of output.
pub subsequent_indent: &'a str,
/// Allow long words to be broken if they cannot fit on a line.
/// When set to `false`, some lines may be longer than
/// `self.width`.
pub break_words: bool,
/// The method for splitting words. If the `hyphenation` feature
/// is enabled, you can use a `hyphenation::Standard` dictionary
/// here to get language-aware hyphenation.
pub splitter: S,
}
impl<'a> Wrapper<'a, HyphenSplitter> {
/// Create a new Wrapper for wrapping at the specified width. By
/// default, we allow words longer than `width` to be broken. A
/// [`HyphenSplitter`] will be used by default for splitting
/// words. See the [`WordSplitter`] trait for other options.
///
/// [`HyphenSplitter`]: struct.HyphenSplitter.html
/// [`WordSplitter`]: trait.WordSplitter.html
pub fn new(width: usize) -> Wrapper<'a, HyphenSplitter> {
Wrapper::with_splitter(width, HyphenSplitter)
}
/// Create a new Wrapper for wrapping text at the current terminal
/// width. If the terminal width cannot be determined (typically
/// because the standard input and output is not connected to a
/// terminal), a width of 80 characters will be used. Other
/// settings use the same defaults as `Wrapper::new`.
///
/// Equivalent to:
///
/// ```no_run
/// # #![allow(unused_variables)]
/// use textwrap::{Wrapper, termwidth};
///
/// let wrapper = Wrapper::new(termwidth());
/// ```
#[cfg(feature = "term_size")]
pub fn with_termwidth() -> Wrapper<'a, HyphenSplitter> {
Wrapper::new(termwidth())
}
}
impl<'a, S: WordSplitter> Wrapper<'a, S> {
/// Use the given [`WordSplitter`] to create a new Wrapper for
/// wrapping at the specified width. By default, we allow words
/// longer than `width` to be broken.
///
/// [`WordSplitter`]: trait.WordSplitter.html
pub fn with_splitter(width: usize, splitter: S) -> Wrapper<'a, S> {
Wrapper {
width: width,
initial_indent: "",
subsequent_indent: "",
break_words: true,
splitter: splitter,
}
}
/// Change [`self.initial_indent`]. The initial indentation is
/// used on the very first line of output.
///
/// # Examples
///
/// Classic paragraph indentation can be achieved by specifying an
/// initial indentation and wrapping each paragraph by itself:
///
/// ```no_run
/// # #![allow(unused_variables)]
/// use textwrap::Wrapper;
///
/// let wrapper = Wrapper::new(15).initial_indent(" ");
/// ```
///
/// [`self.initial_indent`]: #structfield.initial_indent
pub fn initial_indent(self, indent: &'a str) -> Wrapper<'a, S> {
Wrapper {
initial_indent: indent,
..self
}
}
/// Change [`self.subsequent_indent`]. The subsequent indentation
/// is used on lines following the first line of output.
///
/// # Examples
///
/// Combining initial and subsequent indentation lets you format a
/// single paragraph as a bullet list:
///
/// ```no_run
/// # #![allow(unused_variables)]
/// use textwrap::Wrapper;
///
/// let wrapper = Wrapper::new(15)
/// .initial_indent("* ")
/// .subsequent_indent(" ");
/// ```
///
/// [`self.subsequent_indent`]: #structfield.subsequent_indent
pub fn subsequent_indent(self, indent: &'a str) -> Wrapper<'a, S> {
Wrapper {
subsequent_indent: indent,
..self
}
}
/// Change [`self.break_words`]. This controls if words longer
/// than `self.width` can be broken, or if they will be left
/// sticking out into the right margin.
///
/// [`self.break_words`]: #structfield.break_words
pub fn break_words(self, setting: bool) -> Wrapper<'a, S> {
Wrapper {
break_words: setting,
..self
}
}
/// Fill a line of text at `self.width` characters. Strings are
/// wrapped based on their displayed width, not their size in
/// bytes.
///
/// The result is a string with newlines between each line. Use
/// the `wrap` method if you need access to the individual lines.
///
/// # Complexities
///
/// This method simply joins the lines produced by `wrap_iter`. As
/// such, it inherits the O(*n*) time and memory complexity where
/// *n* is the input string length.
///
/// # Examples
///
/// ```
/// use textwrap::Wrapper;
///
/// let wrapper = Wrapper::new(15);
/// assert_eq!(wrapper.fill("Memory safety without garbage collection."),
/// "Memory safety\nwithout garbage\ncollection.");
/// ```
pub fn fill(&self, s: &str) -> String {
// This will avoid reallocation in simple cases (no
// indentation, no hyphenation).
let mut result = String::with_capacity(s.len());
for (i, line) in self.wrap_iter(s).enumerate() {
if i > 0 {
result.push('\n');
}
result.push_str(&line);
}
result
}
/// Wrap a line of text at `self.width` characters. Strings are
/// wrapped based on their displayed width, not their size in
/// bytes.
///
/// # Complexities
///
/// This method simply collects the lines produced by `wrap_iter`.
/// As such, it inherits the O(*n*) overall time and memory
/// complexity where *n* is the input string length.
///
/// # Examples
///
/// ```
/// use textwrap::Wrapper;
///
/// let wrap15 = Wrapper::new(15);
/// assert_eq!(wrap15.wrap("Concurrency without data races."),
/// vec!["Concurrency",
/// "without data",
/// "races."]);
///
/// let wrap20 = Wrapper::new(20);
/// assert_eq!(wrap20.wrap("Concurrency without data races."),
/// vec!["Concurrency without",
/// "data races."]);
/// ```
///
/// Notice that newlines in the input are preserved. This means
/// that they force a line break, regardless of how long the
/// current line is:
///
/// ```
/// use textwrap::Wrapper;
///
/// let wrapper = Wrapper::new(40);
/// assert_eq!(wrapper.wrap("First line.\nSecond line."),
/// vec!["First line.", "Second line."]);
/// ```
///
pub fn wrap(&self, s: &'a str) -> Vec<Cow<'a, str>> {
self.wrap_iter(s).collect::<Vec<_>>()
}
/// Lazily wrap a line of text at `self.width` characters. Strings
/// are wrapped based on their displayed width, not their size in
/// bytes.
///
/// The [`WordSplitter`] stored in [`self.splitter`] is used
/// whenever when a word is too large to fit on the current line.
/// By changing the field, different hyphenation strategies can be
/// implemented.
///
/// # Complexities
///
/// This method returns a [`WrapIter`] iterator which borrows this
/// `Wrapper`. The algorithm used has a linear complexity, so
/// getting the next line from the iterator will take O(*w*) time,
/// where *w* is the wrapping width. Fully processing the iterator
/// will take O(*n*) time for an input string of length *n*.
///
/// When no indentation is used, each line returned is a slice of
/// the input string and the memory overhead is thus constant.
/// Otherwise new memory is allocated for each line returned.
///
/// # Examples
///
/// ```
/// use std::borrow::Cow;
/// use textwrap::Wrapper;
///
/// let wrap20 = Wrapper::new(20);
/// let mut wrap20_iter = wrap20.wrap_iter("Zero-cost abstractions.");
/// assert_eq!(wrap20_iter.next(), Some(Cow::from("Zero-cost")));
/// assert_eq!(wrap20_iter.next(), Some(Cow::from("abstractions.")));
/// assert_eq!(wrap20_iter.next(), None);
///
/// let wrap25 = Wrapper::new(25);
/// let mut wrap25_iter = wrap25.wrap_iter("Zero-cost abstractions.");
/// assert_eq!(wrap25_iter.next(), Some(Cow::from("Zero-cost abstractions.")));
/// assert_eq!(wrap25_iter.next(), None);
/// ```
///
/// [`self.splitter`]: #structfield.splitter
/// [`WordSplitter`]: trait.WordSplitter.html
/// [`WrapIter`]: struct.WrapIter.html
pub fn wrap_iter<'w>(&'w self, s: &'a str) -> WrapIter<'w, 'a, S> {
WrapIter {
wrapper: self,
inner: WrapIterImpl::new(self, s),
}
}
/// Lazily wrap a line of text at `self.width` characters. Strings
/// are wrapped based on their displayed width, not their size in
/// bytes.
///
/// The [`WordSplitter`] stored in [`self.splitter`] is used
/// whenever when a word is too large to fit on the current line.
/// By changing the field, different hyphenation strategies can be
/// implemented.
///
/// # Complexities
///
/// This method consumes the `Wrapper` and returns a
/// [`IntoWrapIter`] iterator. Fully processing the iterator has
/// the same O(*n*) time complexity as [`wrap_iter`], where *n* is
/// the length of the input string.
///
/// # Examples
///
/// ```
/// use std::borrow::Cow;
/// use textwrap::Wrapper;
///
/// let wrap20 = Wrapper::new(20);
/// let mut wrap20_iter = wrap20.into_wrap_iter("Zero-cost abstractions.");
/// assert_eq!(wrap20_iter.next(), Some(Cow::from("Zero-cost")));
/// assert_eq!(wrap20_iter.next(), Some(Cow::from("abstractions.")));
/// assert_eq!(wrap20_iter.next(), None);
/// ```
///
/// [`self.splitter`]: #structfield.splitter
/// [`WordSplitter`]: trait.WordSplitter.html
/// [`IntoWrapIter`]: struct.IntoWrapIter.html
/// [`wrap_iter`]: #method.wrap_iter
pub fn into_wrap_iter(self, s: &'a str) -> IntoWrapIter<'a, S> {
let inner = WrapIterImpl::new(&self, s);
IntoWrapIter {
wrapper: self,
inner: inner,
}
}
}
/// An iterator over the lines of the input string which owns a
/// `Wrapper`. An instance of `IntoWrapIter` is typically obtained
/// through either [`wrap_iter`] or [`Wrapper::into_wrap_iter`].
///
/// Each call of `.next()` method yields a line wrapped in `Some` if the
/// input hasn't been fully processed yet. Otherwise it returns `None`.
///
/// [`wrap_iter`]: fn.wrap_iter.html
/// [`Wrapper::into_wrap_iter`]: struct.Wrapper.html#method.into_wrap_iter
#[derive(Debug)]
pub struct IntoWrapIter<'a, S: WordSplitter> {
wrapper: Wrapper<'a, S>,
inner: WrapIterImpl<'a>,
}
impl<'a, S: WordSplitter> Iterator for IntoWrapIter<'a, S> {
type Item = Cow<'a, str>;
fn next(&mut self) -> Option<Cow<'a, str>> {
self.inner.next(&self.wrapper)
}
}
/// An iterator over the lines of the input string which borrows a
/// `Wrapper`. An instance of `WrapIter` is typically obtained
/// through the [`Wrapper::wrap_iter`] method.
///
/// Each call of `.next()` method yields a line wrapped in `Some` if the
/// input hasn't been fully processed yet. Otherwise it returns `None`.
///
/// [`Wrapper::wrap_iter`]: struct.Wrapper.html#method.wrap_iter
#[derive(Debug)]
pub struct WrapIter<'w, 'a: 'w, S: WordSplitter + 'w> {
wrapper: &'w Wrapper<'a, S>,
inner: WrapIterImpl<'a>,
}
impl<'w, 'a: 'w, S: WordSplitter> Iterator for WrapIter<'w, 'a, S> {
type Item = Cow<'a, str>;
fn next(&mut self) -> Option<Cow<'a, str>> {
self.inner.next(self.wrapper)
}
}
/// Like `char::is_whitespace`, but non-breaking spaces don't count.
#[inline]
fn is_whitespace(ch: char) -> bool {
ch.is_whitespace() && ch != NBSP
}
/// Common implementation details for `WrapIter` and `IntoWrapIter`.
#[derive(Debug)]
struct WrapIterImpl<'a> {
// String to wrap.
source: &'a str,
// CharIndices iterator over self.source.
char_indices: CharIndices<'a>,
// Byte index where the current line starts.
start: usize,
// Byte index of the last place where the string can be split.
split: usize,
// Size in bytes of the character at self.source[self.split].
split_len: usize,
// Width of self.source[self.start..idx].
line_width: usize,
// Width of self.source[self.start..self.split].
line_width_at_split: usize,
// Tracking runs of whitespace characters.
in_whitespace: bool,
// Has iterator finished producing elements?
finished: bool,
}
impl<'a> WrapIterImpl<'a> {
fn new<S: WordSplitter>(wrapper: &Wrapper<'a, S>, s: &'a str) -> WrapIterImpl<'a> {
WrapIterImpl {
source: s,
char_indices: s.char_indices(),
start: 0,
split: 0,
split_len: 0,
line_width: wrapper.initial_indent.width(),
line_width_at_split: wrapper.initial_indent.width(),
in_whitespace: false,
finished: false,
}
}
fn create_result_line<S: WordSplitter>(&self, wrapper: &Wrapper<'a, S>) -> Cow<'a, str> {
if self.start == 0 {
Cow::from(wrapper.initial_indent)
} else {
Cow::from(wrapper.subsequent_indent)
}
}
fn next<S: WordSplitter>(&mut self, wrapper: &Wrapper<'a, S>) -> Option<Cow<'a, str>> {
if self.finished {
return None;
}
while let Some((idx, ch)) = self.char_indices.next() {
let char_width = ch.width().unwrap_or(0);
let char_len = ch.len_utf8();
if ch == '\n' {
self.split = idx;
self.split_len = char_len;
self.line_width_at_split = self.line_width;
self.in_whitespace = false;
// If this is not the final line, return the current line. Otherwise,
// we will return the line with its line break after exiting the loop
if self.split + self.split_len < self.source.len() {
let mut line = self.create_result_line(wrapper);
line += &self.source[self.start..self.split];
self.start = self.split + self.split_len;
self.line_width = wrapper.subsequent_indent.width();
return Some(line);
}
} else if is_whitespace(ch) {
// Extend the previous split or create a new one.
if self.in_whitespace {
self.split_len += char_len;
} else {
self.split = idx;
self.split_len = char_len;
}
self.line_width_at_split = self.line_width + char_width;
self.in_whitespace = true;
} else if self.line_width + char_width > wrapper.width {
// There is no room for this character on the current
// line. Try to split the final word.
self.in_whitespace = false;
let remaining_text = &self.source[self.split + self.split_len..];
let final_word = match remaining_text.find(is_whitespace) {
Some(i) => &remaining_text[..i],
None => remaining_text,
};
let mut hyphen = "";
let splits = wrapper.splitter.split(final_word);
for &(head, hyp, _) in splits.iter().rev() {
if self.line_width_at_split + head.width() + hyp.width() <= wrapper.width {
// We can fit head into the current line.
// Advance the split point by the width of the
// whitespace and the head length.
self.split += self.split_len + head.len();
self.split_len = 0;
hyphen = hyp;
break;
}
}
if self.start >= self.split {
// The word is too big to fit on a single line, so we
// need to split it at the current index.
if wrapper.break_words {
// Break work at current index.
self.split = idx;
self.split_len = 0;
self.line_width_at_split = self.line_width;
} else {
// Add smallest split.
self.split = self.start + splits[0].0.len();
self.split_len = 0;
self.line_width_at_split = self.line_width;
}
}
if self.start < self.split {
let mut line = self.create_result_line(wrapper);
line += &self.source[self.start..self.split];
line += hyphen;
self.start = self.split + self.split_len;
self.line_width += wrapper.subsequent_indent.width();
self.line_width -= self.line_width_at_split;
self.line_width += char_width;
return Some(line);
}
} else {
self.in_whitespace = false;
}
self.line_width += char_width;
}
self.finished = true;
// Add final line.
if self.start < self.source.len() {
let mut line = self.create_result_line(wrapper);
line += &self.source[self.start..];
return Some(line);
}
None
}
}
/// Return the current terminal width. If the terminal width cannot be
/// determined (typically because the standard output is not connected
/// to a terminal), a default width of 80 characters will be used.
///
/// # Examples
///
/// Create a `Wrapper` for the current terminal with a two column
/// margin:
///
/// ```no_run
/// # #![allow(unused_variables)]
/// use textwrap::{Wrapper, NoHyphenation, termwidth};
///
/// let width = termwidth() - 4; // Two columns on each side.
/// let wrapper = Wrapper::with_splitter(width, NoHyphenation)
/// .initial_indent(" ")
/// .subsequent_indent(" ");
/// ```
#[cfg(feature = "term_size")]
pub fn termwidth() -> usize {
term_size::dimensions_stdout().map_or(80, |(w, _)| w)
}
/// Fill a line of text at `width` characters. Strings are wrapped
/// based on their displayed width, not their size in bytes.
///
/// The result is a string with newlines between each line. Use
/// [`wrap`] if you need access to the individual lines or
/// [`wrap_iter`] for its iterator counterpart.
///
/// ```
/// use textwrap::fill;
///
/// assert_eq!(fill("Memory safety without garbage collection.", 15),
/// "Memory safety\nwithout garbage\ncollection.");
/// ```
///
/// This function creates a Wrapper on the fly with default settings.
/// If you need to set a language corpus for automatic hyphenation, or
/// need to fill many strings, then it is suggested to create a Wrapper
/// and call its [`fill` method].
///
/// [`wrap`]: fn.wrap.html
/// [`wrap_iter`]: fn.wrap_iter.html
/// [`fill` method]: struct.Wrapper.html#method.fill
pub fn fill(s: &str, width: usize) -> String {
Wrapper::new(width).fill(s)
}
/// Wrap a line of text at `width` characters. Strings are wrapped
/// based on their displayed width, not their size in bytes.
///
/// This function creates a Wrapper on the fly with default settings.
/// If you need to set a language corpus for automatic hyphenation, or
/// need to wrap many strings, then it is suggested to create a Wrapper
/// and call its [`wrap` method].
///
/// The result is a vector of strings. Use [`wrap_iter`] if you need an
/// iterator version.
///
/// # Examples
///
/// ```
/// use textwrap::wrap;
///
/// assert_eq!(wrap("Concurrency without data races.", 15),
/// vec!["Concurrency",
/// "without data",
/// "races."]);
///
/// assert_eq!(wrap("Concurrency without data races.", 20),
/// vec!["Concurrency without",
/// "data races."]);
/// ```
///
/// [`wrap_iter`]: fn.wrap_iter.html
/// [`wrap` method]: struct.Wrapper.html#method.wrap
pub fn wrap(s: &str, width: usize) -> Vec<Cow<str>> {
Wrapper::new(width).wrap(s)
}
/// Lazily wrap a line of text at `width` characters. Strings are
/// wrapped based on their displayed width, not their size in bytes.
///
/// This function creates a Wrapper on the fly with default settings.
/// It then calls the [`into_wrap_iter`] method. Hence, the return
/// value is an [`IntoWrapIter`], not a [`WrapIter`] as the function
/// name would otherwise suggest.
///
/// If you need to set a language corpus for automatic hyphenation, or
/// need to wrap many strings, then it is suggested to create a Wrapper
/// and call its [`wrap_iter`] or [`into_wrap_iter`] methods.
///
/// # Examples
///
/// ```
/// use std::borrow::Cow;
/// use textwrap::wrap_iter;
///
/// let mut wrap20_iter = wrap_iter("Zero-cost abstractions.", 20);
/// assert_eq!(wrap20_iter.next(), Some(Cow::from("Zero-cost")));
/// assert_eq!(wrap20_iter.next(), Some(Cow::from("abstractions.")));
/// assert_eq!(wrap20_iter.next(), None);
///
/// let mut wrap25_iter = wrap_iter("Zero-cost abstractions.", 25);
/// assert_eq!(wrap25_iter.next(), Some(Cow::from("Zero-cost abstractions.")));
/// assert_eq!(wrap25_iter.next(), None);
/// ```
///
/// [`wrap_iter`]: struct.Wrapper.html#method.wrap_iter
/// [`into_wrap_iter`]: struct.Wrapper.html#method.into_wrap_iter
/// [`IntoWrapIter`]: struct.IntoWrapIter.html
/// [`WrapIter`]: struct.WrapIter.html
pub fn wrap_iter(s: &str, width: usize) -> IntoWrapIter<HyphenSplitter> {
Wrapper::new(width).into_wrap_iter(s)
}
#[cfg(test)]
mod tests {
#[cfg(feature = "hyphenation")]
extern crate hyphenation;
use super::*;
#[cfg(feature = "hyphenation")]
use hyphenation::{Language, Load, Standard};
#[test]
fn no_wrap() {
assert_eq!(wrap("foo", 10), vec!["foo"]);
}
#[test]
fn simple() {
assert_eq!(wrap("foo bar baz", 5), vec!["foo", "bar", "baz"]);
}
#[test]
fn multi_word_on_line() {
assert_eq!(wrap("foo bar baz", 10), vec!["foo bar", "baz"]);
}
#[test]
fn long_word() {
assert_eq!(wrap("foo", 0), vec!["f", "o", "o"]);
}
#[test]
fn long_words() {
assert_eq!(wrap("foo bar", 0), vec!["f", "o", "o", "b", "a", "r"]);
}
#[test]
fn max_width() {
assert_eq!(wrap("foo bar", usize::max_value()), vec!["foo bar"]);
}
#[test]
fn leading_whitespace() {
assert_eq!(wrap(" foo bar", 6), vec![" foo", "bar"]);
}
#[test]
fn trailing_whitespace() {
assert_eq!(wrap("foo bar ", 6), vec!["foo", "bar "]);
}
#[test]
fn interior_whitespace() {
assert_eq!(wrap("foo: bar baz", 10), vec!["foo: bar", "baz"]);
}
#[test]
fn extra_whitespace_start_of_line() {
// Whitespace is only significant inside a line. After a line
// gets too long and is broken, the first word starts in
// column zero and is not indented. The line before might end
// up with trailing whitespace.
assert_eq!(wrap("foo bar", 5), vec!["foo", "bar"]);
}
#[test]
fn issue_99() {
// We did not reset the in_whitespace flag correctly and did
// not handle single-character words after a line break.
assert_eq!(
wrap("aaabbbccc x yyyzzzwww", 9),
vec!["aaabbbccc", "x", "yyyzzzwww"]
);
}
#[test]
fn issue_129() {
// The dash is an em-dash which takes up four bytes. We used
// to panic since we tried to index into the character.
assert_eq!(wrap("x – x", 1), vec!["x", "–", "x"]);
}
#[test]
fn wide_character_handling() {
assert_eq!(wrap("Hello, World!", 15), vec!["Hello, World!"]);
assert_eq!(
wrap("Hello, World!", 15),
vec!["Hello,", "World!"]
);
}
#[test]
fn empty_input_not_indented() {
let wrapper = Wrapper::new(10).initial_indent("!!!");
assert_eq!(wrapper.fill(""), "");
}
#[test]
fn indent_single_line() {
let wrapper = Wrapper::new(10).initial_indent(">>>"); // No trailing space
assert_eq!(wrapper.fill("foo"), ">>>foo");
}
#[test]
fn indent_multiple_lines() {
let wrapper = Wrapper::new(6).initial_indent("* ").subsequent_indent(" ");
assert_eq!(wrapper.wrap("foo bar baz"), vec!["* foo", " bar", " baz"]);
}
#[test]
fn indent_break_words() {
let wrapper = Wrapper::new(5).initial_indent("* ").subsequent_indent(" ");
assert_eq!(wrapper.wrap("foobarbaz"), vec!["* foo", " bar", " baz"]);
}
#[test]
fn hyphens() {
assert_eq!(wrap("foo-bar", 5), vec!["foo-", "bar"]);
}
#[test]
fn trailing_hyphen() {
let wrapper = Wrapper::new(5).break_words(false);
assert_eq!(wrapper.wrap("foobar-"), vec!["foobar-"]);
}
#[test]
fn multiple_hyphens() {
assert_eq!(wrap("foo-bar-baz", 5), vec!["foo-", "bar-", "baz"]);
}
#[test]
fn hyphens_flag() {
let wrapper = Wrapper::new(5).break_words(false);
assert_eq!(
wrapper.wrap("The --foo-bar flag."),
vec!["The", "--foo-", "bar", "flag."]
);
}
#[test]
fn repeated_hyphens() {
let wrapper = Wrapper::new(4).break_words(false);
assert_eq!(wrapper.wrap("foo--bar"), vec!["foo--bar"]);
}
#[test]
fn hyphens_alphanumeric() {
assert_eq!(wrap("Na2-CH4", 5), vec!["Na2-", "CH4"]);
}
#[test]
fn hyphens_non_alphanumeric() {
let wrapper = Wrapper::new(5).break_words(false);
assert_eq!(wrapper.wrap("foo(-)bar"), vec!["foo(-)bar"]);
}
#[test]
fn multiple_splits() {
assert_eq!(wrap("foo-bar-baz", 9), vec!["foo-bar-", "baz"]);
}
#[test]
fn forced_split() {
let wrapper = Wrapper::new(5).break_words(false);
assert_eq!(wrapper.wrap("foobar-baz"), vec!["foobar-", "baz"]);
}
#[test]
fn no_hyphenation() {
let wrapper = Wrapper::with_splitter(8, NoHyphenation);
assert_eq!(wrapper.wrap("foo bar-baz"), vec!["foo", "bar-baz"]);
}
#[test]
#[cfg(feature = "hyphenation")]
fn auto_hyphenation() {
let dictionary = Standard::from_embedded(Language::EnglishUS).unwrap();
let wrapper = Wrapper::new(10);
assert_eq!(
wrapper.wrap("Internationalization"),
vec!["Internatio", "nalization"]
);
let wrapper = Wrapper::with_splitter(10, dictionary);
assert_eq!(
wrapper.wrap("Internationalization"),
vec!["Interna-", "tionaliza-", "tion"]
);
}
#[test]
#[cfg(feature = "hyphenation")]
fn split_len_hyphenation() {
// Test that hyphenation takes the width of the wihtespace
// into account.
let dictionary = Standard::from_embedded(Language::EnglishUS).unwrap();
let wrapper = Wrapper::with_splitter(15, dictionary);
assert_eq!(
wrapper.wrap("garbage collection"),
vec!["garbage col-", "lection"]
);
}
#[test]
#[cfg(feature = "hyphenation")]
fn borrowed_lines() {
// Lines that end with an extra hyphen are owned, the final
// line is borrowed.
use std::borrow::Cow::{Borrowed, Owned};
let dictionary = Standard::from_embedded(Language::EnglishUS).unwrap();
let wrapper = Wrapper::with_splitter(10, dictionary);
let lines = wrapper.wrap("Internationalization");
if let Borrowed(s) = lines[0] {
assert!(false, "should not have been borrowed: {:?}", s);
}
if let Borrowed(s) = lines[1] {
assert!(false, "should not have been borrowed: {:?}", s);
}
if let Owned(ref s) = lines[2] {
assert!(false, "should not have been owned: {:?}", s);
}
}
#[test]
#[cfg(feature = "hyphenation")]
fn auto_hyphenation_with_hyphen() {
let dictionary = Standard::from_embedded(Language::EnglishUS).unwrap();
let wrapper = Wrapper::new(8).break_words(false);
assert_eq!(wrapper.wrap("over-caffinated"), vec!["over-", "caffinated"]);
let wrapper = Wrapper::with_splitter(8, dictionary).break_words(false);
assert_eq!(
wrapper.wrap("over-caffinated"),
vec!["over-", "caffi-", "nated"]
);
}
#[test]
fn break_words() {
assert_eq!(wrap("foobarbaz", 3), vec!["foo", "bar", "baz"]);
}
#[test]
fn break_words_wide_characters() {
assert_eq!(wrap("Hello", 5), vec!["He", "ll", "o"]);
}
#[test]
fn break_words_zero_width() {
assert_eq!(wrap("foobar", 0), vec!["f", "o", "o", "b", "a", "r"]);
}
#[test]
fn break_words_line_breaks() {
assert_eq!(fill("ab\ncdefghijkl", 5), "ab\ncdefg\nhijkl");
assert_eq!(fill("abcdefgh\nijkl", 5), "abcde\nfgh\nijkl");
}
#[test]
fn preserve_line_breaks() {
assert_eq!(fill("test\n", 11), "test\n");
assert_eq!(fill("test\n\na\n\n", 11), "test\n\na\n\n");
assert_eq!(fill("1 3 5 7\n1 3 5 7", 7), "1 3 5 7\n1 3 5 7");
}
#[test]
fn wrap_preserve_line_breaks() {
assert_eq!(fill("1 3 5 7\n1 3 5 7", 5), "1 3 5\n7\n1 3 5\n7");
}
#[test]
fn non_breaking_space() {
let wrapper = Wrapper::new(5).break_words(false);
assert_eq!(wrapper.fill("foo bar baz"), "foo bar baz");
}
#[test]
fn non_breaking_hyphen() {
let wrapper = Wrapper::new(5).break_words(false);
assert_eq!(wrapper.fill("foo‑bar‑baz"), "foo‑bar‑baz");
}
#[test]
fn fill_simple() {
assert_eq!(fill("foo bar baz", 10), "foo bar\nbaz");
}
}