1 files changed, 63 insertions, 0 deletions
diff --git a/third_party/rust/clap_builder/src/output/textwrap/wrap_algorithms.rs b/third_party/rust/clap_builder/src/output/textwrap/wrap_algorithms.rs
new file mode 100644
index 0000000000..34b4fd2b73
--- /dev/null
+++ b/third_party/rust/clap_builder/src/output/textwrap/wrap_algorithms.rs
@@ -0,0 +1,63 @@
+use super::core::display_width;
+
+#[derive(Debug)]
+pub(crate) struct LineWrapper<'w> {
+    hard_width: usize,
+    line_width: usize,
+    carryover: Option<&'w str>,
+}
+
+impl<'w> LineWrapper<'w> {
+    pub(crate) fn new(hard_width: usize) -> Self {
+        Self {
+            hard_width,
+            line_width: 0,
+            carryover: None,
+        }
+    }
+
+    pub(crate) fn reset(&mut self) {
+        self.line_width = 0;
+        self.carryover = None;
+    }
+
+    pub(crate) fn wrap(&mut self, mut words: Vec<&'w str>) -> Vec<&'w str> {
+        if self.carryover.is_none() {
+            if let Some(word) = words.first() {
+                if word.trim().is_empty() {
+                    self.carryover = Some(*word);
+                } else {
+                    self.carryover = Some("");
+                }
+            }
+        }
+
+        let mut i = 0;
+        while i < words.len() {
+            let word = &words[i];
+            let trimmed = word.trim_end();
+            let word_width = display_width(trimmed);
+            let trimmed_delta = word.len() - trimmed.len();
+            if i != 0 && self.hard_width < self.line_width + word_width {
+                if 0 < i {
+                    let last = i - 1;
+                    let trimmed = words[last].trim_end();
+                    words[last] = trimmed;
+                }
+
+                self.line_width = 0;
+                words.insert(i, "\n");
+                i += 1;
+                if let Some(carryover) = self.carryover {
+                    words.insert(i, carryover);
+                    self.line_width += carryover.len();
+                    i += 1;
+                }
+            }
+            self.line_width += word_width + trimmed_delta;
+
+            i += 1;
+        }
+        words
+    }
+}