This file lists the most important changes made in each release of
textwrap
.
This is a major feature release which adds a new generic type
parameter to the Options
struct. This new parameter lets you specify
how words are found in the text.
Common usages of textwrap stays unchanged, but if you previously
spelled out the full type for Options
, you now need to take th extra
type parameter into account. This means that
let options: Options<HyphenSplitter> = Options::new(80);
need to change to
let options: Options<AsciiSpace, HyphenSplitter> = Options::new(80);
You won’t see any chance if you call wrap
directly with a width or
with an Options
constructed on the fly.
This release removes println!
statements which was left behind in
unfill
by mistake.
- #296: Improve house building example with more comments.
- #297: Remove debug
prints in the new
unfill
function.
This release contains a bugfix for indent
and improved handling of
emojis. We’ve also added a new function for formatting text in columns
and functions for reformatting already wrapped text.
- #276: Extend
core::display_width
to handle emojis when the unicode-width Cargo feature is disabled. - #279: Make
indent
preserve existing newlines in the input string. Before,indent("foo", "")
would return"foo\n"
by mistake. It now returns"foo"
instead. - #281: Ensure all
Options
fields have examples. - #282: Add a
wrap_columns
function. - #294: Add new
unfill
andrefill
functions.
This release primarily makes all dependencies optional. This makes it possible to slim down textwrap as needed.
- #254:
impl WordSplitter
forBox<T> where T: WordSplitter
. - #255: Use command line arguments as initial text in interactive example.
- #256: Introduce
fuzz tests for
wrap_optimal_fit
andwrap_first_fit
. - #260: Make the unicode-width dependency optional.
- #261: Make the smawk dependency optional.
This is a bugfix release which fixes a regression in 0.13.0. The bug meant that colored text was wrapped incorrectly.
- #245: Support deleting a word with Ctrl-Backspace in the interactive demo.
- #246: Show build type (debug/release) in interactive demo.
- #249: Correctly compute width while skipping over ANSI escape sequences.
This is a major release which rewrites the core logic, adds many new
features, and fixes a couple of bugs. Most programs which use
textwrap
stays the same, incompatibilities and upgrade notes are
given below.
Clone the repository and run the following to explore the new features in an interactive demo (Linux only):
$ cargo run --example interactive --all-features
- #221: Reformulate wrapping in terms of words with whitespace and penalties.
The core wrapping algorithm has been completely rewritten. This fixed
bugs and simplified the code, while also making it possible to use
textwrap
outside the context of the terminal.
As part of this, trailing whitespace is now discarded consistently from wrapped lines. Before we would inconsistently remove whitespace at the end of wrapped lines, except for the last. Leading whitespace is still preserved.
- #234: Introduce wrapping using an optimal-fit algorithm.
This release adds support for new wrapping algorithm which finds a globally optimal set of line breaks, taking certain penalties into account. As an example, the old algorithm would produce
"To be, or"
"not to be:"
"that is"
"the"
"question"
Notice how the fourth line with “the” is very short. The new algorithm shortens the previous lines slightly to produce fewer short lines:
"To be,"
"or not to"
"be: that"
"is the"
"question"
Use the new textwrap::core::WrapAlgorithm
enum to select between the
new and old algorithm. By default, the new algorithm is used.
The optimal-fit algorithm is inspired by the line breaking algorithm used in TeX, described in the 1981 article Breaking Paragraphs into Lines by Knuth and Plass.
- #226: Add a
fill_inplace
function.
When the text you want to fill is already a temporary String
, you
can now mutate it in-place with fill_inplace
:
let mut greeting = format!("Greetings {}, welcome to the game! You have {} lives left.",
player.name, player.lives);
fill_inplace(&mut greeting, line_width);
This is faster than calling fill
and it will reuse the memory
already allocated for the string.
- #213: Simplify API with only top-level functions.
- #215: Reintroducing
the type parameter on
Options
(previously known asWrapper
). - #219: Allow using
trait objects with
fill
&wrap
. - #227: Replace
WrapOptions
withInto<Options>
.
The Wrapper
struct held the options (line width, indentation, etc)
for wrapping text. It was also the entry point for actually wrapping
the text via its methods such as wrap
, wrap_iter
,
into_wrap_iter
, and fill
methods.
The struct has been replaced by a simpler Options
struct which only
holds options. The Wrapper
methods are gone, their job has been
taken over by the top-level wrap
and fill
functions. The signature
of these functions have changed from
fn fill(s: &str, width: usize) -> String;
fn wrap(s: &str, width: usize) -> Vec<Cow<'_, str>>;
to the more general
fn fill<'a, S, Opt>(text: &str, options: Opt) -> String
where
S: WordSplitter,
Opt: Into<Options<'a, S>>;
fn wrap<'a, S, Opt>(text: &str, options: Opt) -> Vec<Cow<'_, str>>
where
S: WordSplitter,
Opt: Into<Options<'a, S>>;
The Into<Options<'a, S>
bound allows you to pass an usize
(which
is interpreted as the line width) and a full Options
object. This
allows the new functions to work like the old, plus you can now fully
customize the behavior of the wrapping via Options
when needed.
Code that call textwrap::wrap
or textwrap::fill
can remain
unchanged. Code that calls into Wrapper::wrap
or Wrapper::fill
will need to be update. This is a mechanical change, please see
#213 for examples.
Thanks to @CryptJar and @Koxiat for their support in the PRs above!
-
The
wrap_iter
andinto_wrap_iter
methods are gone. This means that lazy iteration is no longer supported: you always get all wrapped lines back as aVec
. This was done to simplify the code and to support the optimal-fit algorithm.The first-fit algorithm could still be implemented in an incremental fashion. Please let us know if this is important to you.
- #206: Change
Wrapper.splitter
fromT: WordSplitter
toBox<dyn WordSplitter>
. - #216: Forbid the use of unsafe code.
This is a bugfix release.
- Fixed #176: Mention compile-time wrapping by linking to
the
textwrap-macros
crate. - Fixed #193: Wrapping with
break_words(false)
was broken and would cause extra whitespace to be inserted when words were longer than the line width.
The code has been updated to the Rust 2018 edition and
each new release of textwrap
will only support the latest stable
version of Rust. Trying to support older Rust versions is a fool's
errand: our dependencies keep releasing new patch versions that
require newer and newer versions of Rust.
The term_size
feature has been replaced by terminal_size
. The API
is unchanged, it is just the name of the Cargo feature that changed.
The hyphenation
feature now only embeds the hyphenation patterns for
US-English. This slims down the dependency.
- Fixed #140: Ignore ANSI escape sequences.
- Fixed #158: Unintended wrapping when using external splitter.
- Fixed #177: Update examples to the 2018 edition.
Due to our dependencies bumping their minimum supported version of Rust, the minimum version of Rust we test against is now 1.22.0.
- Merged #141: Fix
dedent
handling of empty lines and trailing newlines. Thanks @bbqsrc! - Fixed #151: Release of version with hyphenation 0.7.
Due to our dependencies bumping their minimum supported version of Rust, the minimum version of Rust we test against is now 1.17.0.
- Fixed #99: Word broken even though it would fit on line.
- Fixed #107: Automatic hyphenation is off by one.
- Fixed #122: Take newlines into account when wrapping.
- Fixed #129: Panic on string with em-dash.
The dependency on term_size
is now optional, and by default this
feature is not enabled. This is a breaking change for users of
Wrapper::with_termwidth
. Enable the term_size
feature to restore
the old functionality.
Added a regression test for the case where width
is set to
usize::MAX
, thanks @Fraser999! All public structs now implement
Debug
, thanks @hcpl!
- Fixed #101: Make
term_size
an optional dependency.
The Wrapper
stuct is now generic over the type of word splitter
being used. This means less boxing and a nicer API. The
Wrapper::word_splitter
method has been removed. This is a breaking
API change if you used the method to change the word splitter.
The Wrapper
struct has two new methods that will wrap the input text
lazily: Wrapper::wrap_iter
and Wrapper::into_wrap_iter
. Use those
if you will be iterating over the wrapped lines one by one.
Version 0.7.0 changes the return type of Wrapper::wrap
from
Vec<String>
to Vec<Cow<'a, str>>
. This means that the output lines
borrow data from the input string. This is a breaking API change if
you relied on the exact return type of Wrapper::wrap
. Callers of the
textwrap::fill
convenience function will see no breakage.
The above change and other optimizations makes version 0.7.0 roughly 15-30% faster than version 0.6.0.
The squeeze_whitespace
option has been removed since it was
complicating the above optimization. Let us know if this option is
important for you so we can provide a work around.
Version 0.6.0 adds builder methods to Wrapper
for easy one-line
initialization and configuration:
let wrapper = Wrapper::new(60).break_words(false);
It also add a new NoHyphenation
word splitter that will never split
words, not even at existing hyphens.
- Fixed #28: Support not squeezing whitespace.
Version 0.5.0 has breaking API changes. However, this only affects
code using the hyphenation feature. The feature is now optional, so
you will first need to enable the hyphenation
feature as described
above. Afterwards, please change your code from
wrapper.corpus = Some(&corpus);
to
wrapper.splitter = Box::new(corpus);
Other changes include optimizations, so version 0.5.0 is roughly 10-15% faster than version 0.4.0.
- Fixed #19: Add support for finding terminal size.
- Fixed #25: Handle words longer than
self.width
. - Fixed #26: Support custom indentation.
- Fixed #36: Support building without
hyphenation
. - Fixed #39: Respect non-breaking spaces.
Documented complexities and tested these via cargo bench
.
Added support for automatic hyphenation.
Introduced Wrapper
struct. Added support for wrapping on hyphens.
First public release with support for wrapping strings on whitespace.