Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 347 insertions, 0 deletions

diff --git a/third_party/rust/textwrap/src/indentation.rs b/third_party/rust/textwrap/src/indentation.rs
new file mode 100644
index 0000000000..5d90c06156
--- /dev/null
+++ b/third_party/rust/textwrap/src/indentation.rs
@@ -0,0 +1,347 @@
+//! Functions related to adding and removing indentation from lines of
+//! text.
+//!
+//! The functions here can be used to uniformly indent or dedent
+//! (unindent) word wrapped lines of text.
+
+/// Indent each line by the given prefix.
+///
+/// # Examples
+///
+/// ```
+/// use textwrap::indent;
+///
+/// assert_eq!(indent("First line.\nSecond line.\n", "  "),
+///            "  First line.\n  Second line.\n");
+/// ```
+///
+/// When indenting, trailing whitespace is stripped from the prefix.
+/// This means that empty lines remain empty afterwards:
+///
+/// ```
+/// use textwrap::indent;
+///
+/// assert_eq!(indent("First line.\n\n\nSecond line.\n", "  "),
+///            "  First line.\n\n\n  Second line.\n");
+/// ```
+///
+/// Notice how `"\n\n\n"` remained as `"\n\n\n"`.
+///
+/// This feature is useful when you want to indent text and have a
+/// space between your prefix and the text. In this case, you _don't_
+/// want a trailing space on empty lines:
+///
+/// ```
+/// use textwrap::indent;
+///
+/// assert_eq!(indent("foo = 123\n\nprint(foo)\n", "# "),
+///            "# foo = 123\n#\n# print(foo)\n");
+/// ```
+///
+/// Notice how `"\n\n"` became `"\n#\n"` instead of `"\n# \n"` which
+/// would have trailing whitespace.
+///
+/// Leading and trailing whitespace coming from the text itself is
+/// kept unchanged:
+///
+/// ```
+/// use textwrap::indent;
+///
+/// assert_eq!(indent(" \t  Foo   ", "->"), "-> \t  Foo   ");
+/// ```
+pub fn indent(s: &str, prefix: &str) -> String {
+    // We know we'll need more than s.len() bytes for the output, but
+    // without counting '\n' characters (which is somewhat slow), we
+    // don't know exactly how much. However, we can preemptively do
+    // the first doubling of the output size.
+    let mut result = String::with_capacity(2 * s.len());
+    let trimmed_prefix = prefix.trim_end();
+    for (idx, line) in s.split_terminator('\n').enumerate() {
+        if idx > 0 {
+            result.push('\n');
+        }
+        if line.trim().is_empty() {
+            result.push_str(trimmed_prefix);
+        } else {
+            result.push_str(prefix);
+        }
+        result.push_str(line);
+    }
+    if s.ends_with('\n') {
+        // split_terminator will have eaten the final '\n'.
+        result.push('\n');
+    }
+    result
+}
+
+/// Removes common leading whitespace from each line.
+///
+/// This function will look at each non-empty line and determine the
+/// maximum amount of whitespace that can be removed from all lines:
+///
+/// ```
+/// use textwrap::dedent;
+///
+/// assert_eq!(dedent("
+///     1st line
+///       2nd line
+///     3rd line
+/// "), "
+/// 1st line
+///   2nd line
+/// 3rd line
+/// ");
+/// ```
+pub fn dedent(s: &str) -> String {
+    let mut prefix = "";
+    let mut lines = s.lines();
+
+    // We first search for a non-empty line to find a prefix.
+    for line in &mut lines {
+        let mut whitespace_idx = line.len();
+        for (idx, ch) in line.char_indices() {
+            if !ch.is_whitespace() {
+                whitespace_idx = idx;
+                break;
+            }
+        }
+
+        // Check if the line had anything but whitespace
+        if whitespace_idx < line.len() {
+            prefix = &line[..whitespace_idx];
+            break;
+        }
+    }
+
+    // We then continue looking through the remaining lines to
+    // possibly shorten the prefix.
+    for line in &mut lines {
+        let mut whitespace_idx = line.len();
+        for ((idx, a), b) in line.char_indices().zip(prefix.chars()) {
+            if a != b {
+                whitespace_idx = idx;
+                break;
+            }
+        }
+
+        // Check if the line had anything but whitespace and if we
+        // have found a shorter prefix
+        if whitespace_idx < line.len() && whitespace_idx < prefix.len() {
+            prefix = &line[..whitespace_idx];
+        }
+    }
+
+    // We now go over the lines a second time to build the result.
+    let mut result = String::new();
+    for line in s.lines() {
+        if line.starts_with(&prefix) && line.chars().any(|c| !c.is_whitespace()) {
+            let (_, tail) = line.split_at(prefix.len());
+            result.push_str(tail);
+        }
+        result.push('\n');
+    }
+
+    if result.ends_with('\n') && !s.ends_with('\n') {
+        let new_len = result.len() - 1;
+        result.truncate(new_len);
+    }
+
+    result
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn indent_empty() {
+        assert_eq!(indent("\n", "  "), "\n");
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn indent_nonempty() {
+        let text = [
+            "  foo\n",
+            "bar\n",
+            "  baz\n",
+        ].join("");
+        let expected = [
+            "//   foo\n",
+            "// bar\n",
+            "//   baz\n",
+        ].join("");
+        assert_eq!(indent(&text, "// "), expected);
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn indent_empty_line() {
+        let text = [
+            "  foo",
+            "bar",
+            "",
+            "  baz",
+        ].join("\n");
+        let expected = [
+            "//   foo",
+            "// bar",
+            "//",
+            "//   baz",
+        ].join("\n");
+        assert_eq!(indent(&text, "// "), expected);
+    }
+
+    #[test]
+    fn dedent_empty() {
+        assert_eq!(dedent(""), "");
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn dedent_multi_line() {
+        let x = [
+            "    foo",
+            "  bar",
+            "    baz",
+        ].join("\n");
+        let y = [
+            "  foo",
+            "bar",
+            "  baz"
+        ].join("\n");
+        assert_eq!(dedent(&x), y);
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn dedent_empty_line() {
+        let x = [
+            "    foo",
+            "  bar",
+            "   ",
+            "    baz"
+        ].join("\n");
+        let y = [
+            "  foo",
+            "bar",
+            "",
+            "  baz"
+        ].join("\n");
+        assert_eq!(dedent(&x), y);
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn dedent_blank_line() {
+        let x = [
+            "      foo",
+            "",
+            "        bar",
+            "          foo",
+            "          bar",
+            "          baz",
+        ].join("\n");
+        let y = [
+            "foo",
+            "",
+            "  bar",
+            "    foo",
+            "    bar",
+            "    baz",
+        ].join("\n");
+        assert_eq!(dedent(&x), y);
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn dedent_whitespace_line() {
+        let x = [
+            "      foo",
+            " ",
+            "        bar",
+            "          foo",
+            "          bar",
+            "          baz",
+        ].join("\n");
+        let y = [
+            "foo",
+            "",
+            "  bar",
+            "    foo",
+            "    bar",
+            "    baz",
+        ].join("\n");
+        assert_eq!(dedent(&x), y);
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn dedent_mixed_whitespace() {
+        let x = [
+            "\tfoo",
+            "  bar",
+        ].join("\n");
+        let y = [
+            "\tfoo",
+            "  bar",
+        ].join("\n");
+        assert_eq!(dedent(&x), y);
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn dedent_tabbed_whitespace() {
+        let x = [
+            "\t\tfoo",
+            "\t\t\tbar",
+        ].join("\n");
+        let y = [
+            "foo",
+            "\tbar",
+        ].join("\n");
+        assert_eq!(dedent(&x), y);
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn dedent_mixed_tabbed_whitespace() {
+        let x = [
+            "\t  \tfoo",
+            "\t  \t\tbar",
+        ].join("\n");
+        let y = [
+            "foo",
+            "\tbar",
+        ].join("\n");
+        assert_eq!(dedent(&x), y);
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn dedent_mixed_tabbed_whitespace2() {
+        let x = [
+            "\t  \tfoo",
+            "\t    \tbar",
+        ].join("\n");
+        let y = [
+            "\tfoo",
+            "  \tbar",
+        ].join("\n");
+        assert_eq!(dedent(&x), y);
+    }
+
+    #[test]
+    #[rustfmt::skip]
+    fn dedent_preserve_no_terminating_newline() {
+        let x = [
+            "  foo",
+            "    bar",
+        ].join("\n");
+        let y = [
+            "foo",
+            "  bar",
+        ].join("\n");
+        assert_eq!(dedent(&x), y);
+    }
+}