Add structopt dependency in version 0.3.7

This patch series replaces argparse with structopt in the argument
handling code. As a first step, we need structopt as a dependency.

Import subrepo structopt/:structopt at efbdda4753592e27bc430fb01f7b9650b2f3174d
Import subrepo bitflags/:bitflags at 30668016aca6bd3b02c766e8347e0b4080d4c296
Import subrepo clap/:clap at 784524f7eb193e35f81082cc69454c8c21b948f7
Import subrepo heck/:heck at 093d56fbf001e1506e56dbfa38631d99b1066df1
Import subrepo proc-macro-error/:proc-macro-error at 6c4cfe79a622c5de8ae68557993542be46eacae2
Import subrepo proc-macro2/:proc-macro2 at d5d48eddca4566e5438e8a2cbed4a74e049544de
Import subrepo quote/:quote at 727436c6c137b20f0f34dde5d8fda2679b9747ad
Import subrepo rustversion/:rustversion at 0c5663313516263059ce9059ef81fc7a1cf655ca
Import subrepo syn-mid/:syn-mid at 5d3d85414a9e6674e1857ec22a87b96e04a6851a
Import subrepo syn/:syn at e87c27e87f6f4ef8919d0372bdb056d53ef0d8f3
Import subrepo textwrap/:textwrap at abcd618beae3f74841032aa5b53c1086b0a57ca2
Import subrepo unicode-segmentation/:unicode-segmentation at 637c9874c4fe0c205ff27787faf150a40295c6c3
Import subrepo unicode-width/:unicode-width at 3033826f8bf05e82724140a981d5941e48fce393
Import subrepo unicode-xid/:unicode-xid at 4baae9fffb156ba229665b972a9cd5991787ceb7

1 files changed, 139 insertions, 0 deletions

diff --git a/textwrap/src/splitting.rs b/textwrap/src/splitting.rs
new file mode 100644
index 0000000..f6b65af
--- /dev/null
+++ b/textwrap/src/splitting.rs
@@ -0,0 +1,139 @@
+//! Word splitting functionality.
+//!
+//! To wrap text into lines, long words sometimes need to be split
+//! across lines. The [`WordSplitter`] trait defines this
+//! functionality. [`HyphenSplitter`] is the default implementation of
+//! this treat: it will simply split words on existing hyphens.
+
+#[cfg(feature = "hyphenation")]
+use hyphenation::{Hyphenator, Standard};
+
+/// An interface for splitting words.
+///
+/// When the [`wrap_iter`] method will try to fit text into a line, it
+/// will eventually find a word that it too large the current text
+/// width. It will then call the currently configured `WordSplitter` to
+/// have it attempt to split the word into smaller parts. This trait
+/// describes that functionality via the [`split`] method.
+///
+/// If the `textwrap` crate has been compiled with the `hyphenation`
+/// feature enabled, you will find an implementation of `WordSplitter`
+/// by the `hyphenation::language::Corpus` struct. Use this struct for
+/// language-aware hyphenation. See the [`hyphenation` documentation]
+/// for details.
+///
+/// [`wrap_iter`]: ../struct.Wrapper.html#method.wrap_iter
+/// [`split`]: #tymethod.split
+/// [`hyphenation` documentation]: https://docs.rs/hyphenation/
+pub trait WordSplitter {
+    /// Return all possible splits of word. Each split is a triple
+    /// with a head, a hyphen, and a tail where `head + &hyphen +
+    /// &tail == word`. The hyphen can be empty if there is already a
+    /// hyphen in the head.
+    ///
+    /// The splits should go from smallest to longest and should
+    /// include no split at all. So the word "technology" could be
+    /// split into
+    ///
+    /// ```no_run
+    /// vec![("tech", "-", "nology"),
+    ///      ("technol", "-", "ogy"),
+    ///      ("technolo", "-", "gy"),
+    ///      ("technology", "", "")];
+    /// ```
+    fn split<'w>(&self, word: &'w str) -> Vec<(&'w str, &'w str, &'w str)>;
+}
+
+/// Use this as a [`Wrapper.splitter`] to avoid any kind of
+/// hyphenation:
+///
+/// ```
+/// use textwrap::{Wrapper, NoHyphenation};
+///
+/// let wrapper = Wrapper::with_splitter(8, NoHyphenation);
+/// assert_eq!(wrapper.wrap("foo bar-baz"), vec!["foo", "bar-baz"]);
+/// ```
+///
+/// [`Wrapper.splitter`]: ../struct.Wrapper.html#structfield.splitter
+#[derive(Clone, Debug)]
+pub struct NoHyphenation;
+
+/// `NoHyphenation` implements `WordSplitter` by not splitting the
+/// word at all.
+impl WordSplitter for NoHyphenation {
+    fn split<'w>(&self, word: &'w str) -> Vec<(&'w str, &'w str, &'w str)> {
+        vec![(word, "", "")]
+    }
+}
+
+/// Simple and default way to split words: splitting on existing
+/// hyphens only.
+///
+/// You probably don't need to use this type since it's already used
+/// by default by `Wrapper::new`.
+#[derive(Clone, Debug)]
+pub struct HyphenSplitter;
+
+/// `HyphenSplitter` is the default `WordSplitter` used by
+/// `Wrapper::new`. It will split words on any existing hyphens in the
+/// word.
+///
+/// It will only use hyphens that are surrounded by alphanumeric
+/// characters, which prevents a word like "--foo-bar" from being
+/// split on the first or second hyphen.
+impl WordSplitter for HyphenSplitter {
+    fn split<'w>(&self, word: &'w str) -> Vec<(&'w str, &'w str, &'w str)> {
+        let mut triples = Vec::new();
+        // Split on hyphens, smallest split first. We only use hyphens
+        // that are surrounded by alphanumeric characters. This is to
+        // avoid splitting on repeated hyphens, such as those found in
+        // --foo-bar.
+        let mut char_indices = word.char_indices();
+        // Early return if the word is empty.
+        let mut prev = match char_indices.next() {
+            None => return vec![(word, "", "")],
+            Some((_, ch)) => ch,
+        };
+
+        // Find current word, or return early if the word only has a
+        // single character.
+        let (mut idx, mut cur) = match char_indices.next() {
+            None => return vec![(word, "", "")],
+            Some((idx, cur)) => (idx, cur),
+        };
+
+        for (i, next) in char_indices {
+            if prev.is_alphanumeric() && cur == '-' && next.is_alphanumeric() {
+                let (head, tail) = word.split_at(idx + 1);
+                triples.push((head, "", tail));
+            }
+            prev = cur;
+            idx = i;
+            cur = next;
+        }
+
+        // Finally option is no split at all.
+        triples.push((word, "", ""));
+
+        triples
+    }
+}
+
+/// A hyphenation dictionary can be used to do language-specific
+/// hyphenation using patterns from the hyphenation crate.
+#[cfg(feature = "hyphenation")]
+impl WordSplitter for Standard {
+    fn split<'w>(&self, word: &'w str) -> Vec<(&'w str, &'w str, &'w str)> {
+        // Find splits based on language dictionary.
+        let mut triples = Vec::new();
+        for n in self.hyphenate(word).breaks {
+            let (head, tail) = word.split_at(n);
+            let hyphen = if head.ends_with('-') { "" } else { "-" };
+            triples.push((head, hyphen, tail));
+        }
+        // Finally option is no split at all.
+        triples.push((word, "", ""));
+
+        triples
+    }
+}