Adding upstream version 115.7.0esr.upstream/115.7.0esr

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

9 files changed, 859 insertions, 0 deletions

diff --git a/third_party/rust/heck/src/kebab.rs b/third_party/rust/heck/src/kebab.rs
new file mode 100644
index 0000000000..6cce5a56bb
--- /dev/null
+++ b/third_party/rust/heck/src/kebab.rs
@@ -0,0 +1,70 @@
+use std::fmt;
+
+use crate::{lowercase, transform};
+
+/// This trait defines a kebab case conversion.
+///
+/// In kebab-case, word boundaries are indicated by hyphens.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToKebabCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(sentence.to_kebab_case(), "we-are-going-to-inherit-the-earth");
+/// ```
+pub trait ToKebabCase: ToOwned {
+    /// Convert this type to kebab case.
+    fn to_kebab_case(&self) -> Self::Owned;
+}
+
+impl ToKebabCase for str {
+    fn to_kebab_case(&self) -> Self::Owned {
+        AsKebabCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a kebab case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsKebabCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(format!("{}", AsKebabCase(sentence)), "we-are-going-to-inherit-the-earth");
+/// ```
+pub struct AsKebabCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsKebabCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), lowercase, |f| write!(f, "-"), f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToKebabCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_kebab_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "camel-case");
+    t!(test2: "This is Human case." => "this-is-human-case");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "mixed-up-camel-case-with-some-spaces");
+    t!(test4: "mixed_up_ snake_case with some _spaces" => "mixed-up-snake-case-with-some-spaces");
+    t!(test5: "kebab-case" => "kebab-case");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "shouty-snake-case");
+    t!(test7: "snake_case" => "snake-case");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "this-contains-all-kinds-of-word-boundaries");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baffle" => "xσxς-baffle");
+    t!(test10: "XMLHttpRequest" => "xml-http-request");
+}
diff --git a/third_party/rust/heck/src/lib.rs b/third_party/rust/heck/src/lib.rs
new file mode 100644
index 0000000000..49bfb0efde
--- /dev/null
+++ b/third_party/rust/heck/src/lib.rs
@@ -0,0 +1,209 @@
+//! **heck** is a case conversion library.
+//!
+//! This library exists to provide case conversion between common cases like
+//! CamelCase and snake_case. It is intended to be unicode aware, internally
+//! consistent, and reasonably well performing.
+//!
+//! ## Definition of a word boundary
+//!
+//! Word boundaries are defined as the "unicode words" defined in the
+//! `unicode_segmentation` library, as well as within those words in this
+//! manner:
+//!
+//! 1. All underscore characters are considered word boundaries.
+//! 2. If an uppercase character is followed by lowercase letters, a word
+//! boundary is considered to be just prior to that uppercase character.
+//! 3. If multiple uppercase characters are consecutive, they are considered to
+//! be within a single word, except that the last will be part of the next word
+//! if it is followed by lowercase characters (see rule 2).
+//!
+//! That is, "HelloWorld" is segmented `Hello|World` whereas "XMLHttpRequest" is
+//! segmented `XML|Http|Request`.
+//!
+//! Characters not within words (such as spaces, punctuations, and underscores)
+//! are not included in the output string except as they are a part of the case
+//! being converted to. Multiple adjacent word boundaries (such as a series of
+//! underscores) are folded into one. ("hello__world" in snake case is therefore
+//! "hello_world", not the exact same string). Leading or trailing word boundary
+//! indicators are dropped, except insofar as CamelCase capitalizes the first
+//! word.
+//!
+//! ### Cases contained in this library:
+//!
+//! 1. UpperCamelCase
+//! 2. lowerCamelCase
+//! 3. snake_case
+//! 4. kebab-case
+//! 5. SHOUTY_SNAKE_CASE
+//! 6. Title Case
+//! 7. SHOUTY-KEBAB-CASE
+//! 8. Train-Case
+#![deny(missing_docs)]
+#![forbid(unsafe_code)]
+
+mod kebab;
+mod lower_camel;
+mod shouty_kebab;
+mod shouty_snake;
+mod snake;
+mod title;
+mod train;
+mod upper_camel;
+
+pub use kebab::{AsKebabCase, ToKebabCase};
+pub use lower_camel::{AsLowerCamelCase, ToLowerCamelCase};
+pub use shouty_kebab::{AsShoutyKebabCase, ToShoutyKebabCase};
+pub use shouty_snake::{
+    AsShoutySnakeCase, AsShoutySnakeCase as AsShoutySnekCase, ToShoutySnakeCase, ToShoutySnekCase,
+};
+pub use snake::{AsSnakeCase, AsSnakeCase as AsSnekCase, ToSnakeCase, ToSnekCase};
+pub use title::{AsTitleCase, ToTitleCase};
+pub use train::{AsTrainCase, ToTrainCase};
+pub use upper_camel::{
+    AsUpperCamelCase, AsUpperCamelCase as AsPascalCase, ToPascalCase, ToUpperCamelCase,
+};
+
+use std::fmt;
+
+#[cfg(feature = "unicode")]
+fn get_iterator(s: &str) -> unicode_segmentation::UnicodeWords {
+    use unicode_segmentation::UnicodeSegmentation;
+    s.unicode_words()
+}
+#[cfg(not(feature = "unicode"))]
+fn get_iterator(s: &str) -> impl Iterator<Item = &str> {
+    s.split(|letter: char| !letter.is_ascii_alphanumeric())
+}
+
+fn transform<F, G>(
+    s: &str,
+    mut with_word: F,
+    mut boundary: G,
+    f: &mut fmt::Formatter,
+) -> fmt::Result
+where
+    F: FnMut(&str, &mut fmt::Formatter) -> fmt::Result,
+    G: FnMut(&mut fmt::Formatter) -> fmt::Result,
+{
+    /// Tracks the current 'mode' of the transformation algorithm as it scans
+    /// the input string.
+    ///
+    /// The mode is a tri-state which tracks the case of the last cased
+    /// character of the current word. If there is no cased character
+    /// (either lowercase or uppercase) since the previous word boundary,
+    /// than the mode is `Boundary`. If the last cased character is lowercase,
+    /// then the mode is `Lowercase`. Othertherwise, the mode is
+    /// `Uppercase`.
+    #[derive(Clone, Copy, PartialEq)]
+    enum WordMode {
+        /// There have been no lowercase or uppercase characters in the current
+        /// word.
+        Boundary,
+        /// The previous cased character in the current word is lowercase.
+        Lowercase,
+        /// The previous cased character in the current word is uppercase.
+        Uppercase,
+    }
+
+    let mut first_word = true;
+
+    for word in get_iterator(s) {
+        let mut char_indices = word.char_indices().peekable();
+        let mut init = 0;
+        let mut mode = WordMode::Boundary;
+
+        while let Some((i, c)) = char_indices.next() {
+            // Skip underscore characters
+            if c == '_' {
+                if init == i {
+                    init += 1;
+                }
+                continue;
+            }
+
+            if let Some(&(next_i, next)) = char_indices.peek() {
+                // The mode including the current character, assuming the
+                // current character does not result in a word boundary.
+                let next_mode = if c.is_lowercase() {
+                    WordMode::Lowercase
+                } else if c.is_uppercase() {
+                    WordMode::Uppercase
+                } else {
+                    mode
+                };
+
+                // Word boundary after if next is underscore or current is
+                // not uppercase and next is uppercase
+                if next == '_' || (next_mode == WordMode::Lowercase && next.is_uppercase()) {
+                    if !first_word {
+                        boundary(f)?;
+                    }
+                    with_word(&word[init..next_i], f)?;
+                    first_word = false;
+                    init = next_i;
+                    mode = WordMode::Boundary;
+
+                // Otherwise if current and previous are uppercase and next
+                // is lowercase, word boundary before
+                } else if mode == WordMode::Uppercase && c.is_uppercase() && next.is_lowercase() {
+                    if !first_word {
+                        boundary(f)?;
+                    } else {
+                        first_word = false;
+                    }
+                    with_word(&word[init..i], f)?;
+                    init = i;
+                    mode = WordMode::Boundary;
+
+                // Otherwise no word boundary, just update the mode
+                } else {
+                    mode = next_mode;
+                }
+            } else {
+                // Collect trailing characters as a word
+                if !first_word {
+                    boundary(f)?;
+                } else {
+                    first_word = false;
+                }
+                with_word(&word[init..], f)?;
+                break;
+            }
+        }
+    }
+
+    Ok(())
+}
+
+fn lowercase(s: &str, f: &mut fmt::Formatter) -> fmt::Result {
+    let mut chars = s.chars().peekable();
+    while let Some(c) = chars.next() {
+        if c == 'Σ' && chars.peek().is_none() {
+            write!(f, "ς")?;
+        } else {
+            write!(f, "{}", c.to_lowercase())?;
+        }
+    }
+
+    Ok(())
+}
+
+fn uppercase(s: &str, f: &mut fmt::Formatter) -> fmt::Result {
+    for c in s.chars() {
+        write!(f, "{}", c.to_uppercase())?;
+    }
+
+    Ok(())
+}
+
+fn capitalize(s: &str, f: &mut fmt::Formatter) -> fmt::Result {
+    let mut char_indices = s.char_indices();
+    if let Some((_, c)) = char_indices.next() {
+        write!(f, "{}", c.to_uppercase())?;
+        if let Some((i, _)) = char_indices.next() {
+            lowercase(&s[i..], f)?;
+        }
+    }
+
+    Ok(())
+}
diff --git a/third_party/rust/heck/src/lower_camel.rs b/third_party/rust/heck/src/lower_camel.rs
new file mode 100644
index 0000000000..f1d6c94cdd
--- /dev/null
+++ b/third_party/rust/heck/src/lower_camel.rs
@@ -0,0 +1,85 @@
+use std::fmt;
+
+use crate::{capitalize, lowercase, transform};
+
+/// This trait defines a lower camel case conversion.
+///
+/// In lowerCamelCase, word boundaries are indicated by capital letters,
+/// excepting the first word.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToLowerCamelCase;
+///
+/// let sentence = "It is we who built these palaces and cities.";
+/// assert_eq!(sentence.to_lower_camel_case(), "itIsWeWhoBuiltThesePalacesAndCities");
+/// ```
+pub trait ToLowerCamelCase: ToOwned {
+    /// Convert this type to lower camel case.
+    fn to_lower_camel_case(&self) -> Self::Owned;
+}
+
+impl ToLowerCamelCase for str {
+    fn to_lower_camel_case(&self) -> String {
+        AsLowerCamelCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a lower camel case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsLowerCamelCase;
+///
+/// let sentence = "It is we who built these palaces and cities.";
+/// assert_eq!(format!("{}", AsLowerCamelCase(sentence)), "itIsWeWhoBuiltThesePalacesAndCities");
+/// ```
+pub struct AsLowerCamelCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsLowerCamelCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let mut first = true;
+        transform(
+            self.0.as_ref(),
+            |s, f| {
+                if first {
+                    first = false;
+                    lowercase(s, f)
+                } else {
+                    capitalize(s, f)
+                }
+            },
+            |_| Ok(()),
+            f,
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToLowerCamelCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_lower_camel_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "camelCase");
+    t!(test2: "This is Human case." => "thisIsHumanCase");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "mixedUpCamelCaseWithSomeSpaces");
+    t!(test4: "mixed_up_ snake_case, with some _spaces" => "mixedUpSnakeCaseWithSomeSpaces");
+    t!(test5: "kebab-case" => "kebabCase");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "shoutySnakeCase");
+    t!(test7: "snake_case" => "snakeCase");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "thisContainsAllKindsOfWordBoundaries");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baffle" => "xσxςBaffle");
+    t!(test10: "XMLHttpRequest" => "xmlHttpRequest");
+    // TODO unicode tests
+}
diff --git a/third_party/rust/heck/src/shouty_kebab.rs b/third_party/rust/heck/src/shouty_kebab.rs
new file mode 100644
index 0000000000..e679978bef
--- /dev/null
+++ b/third_party/rust/heck/src/shouty_kebab.rs
@@ -0,0 +1,72 @@
+use std::fmt;
+
+use crate::{transform, uppercase};
+
+/// This trait defines a shouty kebab case conversion.
+///
+/// In SHOUTY-KEBAB-CASE, word boundaries are indicated by hyphens and all
+/// words are in uppercase.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToShoutyKebabCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(sentence.to_shouty_kebab_case(), "WE-ARE-GOING-TO-INHERIT-THE-EARTH");
+/// ```
+pub trait ToShoutyKebabCase: ToOwned {
+    /// Convert this type to shouty kebab case.
+    fn to_shouty_kebab_case(&self) -> Self::Owned;
+}
+
+impl ToShoutyKebabCase for str {
+    fn to_shouty_kebab_case(&self) -> Self::Owned {
+        AsShoutyKebabCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a kebab case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsShoutyKebabCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(format!("{}", AsShoutyKebabCase(sentence)), "WE-ARE-GOING-TO-INHERIT-THE-EARTH");
+/// ```
+pub struct AsShoutyKebabCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsShoutyKebabCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), uppercase, |f| write!(f, "-"), f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToShoutyKebabCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_shouty_kebab_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "CAMEL-CASE");
+    t!(test2: "This is Human case." => "THIS-IS-HUMAN-CASE");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "MIXED-UP-CAMEL-CASE-WITH-SOME-SPACES");
+    t!(test4: "mixed_up_ snake_case with some _spaces" => "MIXED-UP-SNAKE-CASE-WITH-SOME-SPACES");
+    t!(test5: "kebab-case" => "KEBAB-CASE");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "SHOUTY-SNAKE-CASE");
+    t!(test7: "snake_case" => "SNAKE-CASE");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "THIS-CONTAINS-ALL-KINDS-OF-WORD-BOUNDARIES");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baffle" => "XΣXΣ-BAFFLE");
+    t!(test10: "XMLHttpRequest" => "XML-HTTP-REQUEST");
+    t!(test11: "SHOUTY-KEBAB-CASE" => "SHOUTY-KEBAB-CASE");
+}
diff --git a/third_party/rust/heck/src/shouty_snake.rs b/third_party/rust/heck/src/shouty_snake.rs
new file mode 100644
index 0000000000..d5043755e6
--- /dev/null
+++ b/third_party/rust/heck/src/shouty_snake.rs
@@ -0,0 +1,85 @@
+use std::fmt;
+
+use crate::{transform, uppercase};
+
+/// This trait defines a shouty snake case conversion.
+///
+/// In SHOUTY_SNAKE_CASE, word boundaries are indicated by underscores and all
+/// words are in uppercase.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToShoutySnakeCase;
+///
+/// let sentence = "That world is growing in this minute.";
+/// assert_eq!(sentence.to_shouty_snake_case(), "THAT_WORLD_IS_GROWING_IN_THIS_MINUTE");
+/// ```
+pub trait ToShoutySnakeCase: ToOwned {
+    /// Convert this type to shouty snake case.
+    fn to_shouty_snake_case(&self) -> Self::Owned;
+}
+
+/// Oh heck, ToShoutySnekCase is an alias for ToShoutySnakeCase. See
+/// ToShoutySnakeCase for more documentation.
+pub trait ToShoutySnekCase: ToOwned {
+    /// CONVERT THIS TYPE TO SNEK CASE.
+    #[allow(non_snake_case)]
+    fn TO_SHOUTY_SNEK_CASE(&self) -> Self::Owned;
+}
+
+impl<T: ?Sized + ToShoutySnakeCase> ToShoutySnekCase for T {
+    fn TO_SHOUTY_SNEK_CASE(&self) -> Self::Owned {
+        self.to_shouty_snake_case()
+    }
+}
+
+impl ToShoutySnakeCase for str {
+    fn to_shouty_snake_case(&self) -> Self::Owned {
+        AsShoutySnakeCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a shouty snake  case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsShoutySnakeCase;
+///
+/// let sentence = "That world is growing in this minute.";
+/// assert_eq!(format!("{}", AsShoutySnakeCase(sentence)), "THAT_WORLD_IS_GROWING_IN_THIS_MINUTE");
+/// ```
+pub struct AsShoutySnakeCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsShoutySnakeCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), uppercase, |f| write!(f, "_"), f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToShoutySnakeCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_shouty_snake_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "CAMEL_CASE");
+    t!(test2: "This is Human case." => "THIS_IS_HUMAN_CASE");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "MIXED_UP_CAMEL_CASE_WITH_SOME_SPACES");
+    t!(test4: "mixed_up_snake_case with some _spaces" => "MIXED_UP_SNAKE_CASE_WITH_SOME_SPACES");
+    t!(test5: "kebab-case" => "KEBAB_CASE");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "SHOUTY_SNAKE_CASE");
+    t!(test7: "snake_case" => "SNAKE_CASE");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "THIS_CONTAINS_ALL_KINDS_OF_WORD_BOUNDARIES");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baffle" => "XΣXΣ_BAFFLE");
+    t!(test10: "XMLHttpRequest" => "XML_HTTP_REQUEST");
+}
diff --git a/third_party/rust/heck/src/snake.rs b/third_party/rust/heck/src/snake.rs
new file mode 100644
index 0000000000..127a8642f7
--- /dev/null
+++ b/third_party/rust/heck/src/snake.rs
@@ -0,0 +1,98 @@
+use std::fmt;
+
+use crate::{lowercase, transform};
+
+/// This trait defines a snake case conversion.
+///
+/// In snake_case, word boundaries are indicated by underscores.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToSnakeCase;
+///
+/// let sentence = "We carry a new world here, in our hearts.";
+/// assert_eq!(sentence.to_snake_case(), "we_carry_a_new_world_here_in_our_hearts");
+/// ```
+pub trait ToSnakeCase: ToOwned {
+    /// Convert this type to snake case.
+    fn to_snake_case(&self) -> Self::Owned;
+}
+
+/// Oh heck, SnekCase is an alias for ToSnakeCase. See ToSnakeCase for
+/// more documentation.
+pub trait ToSnekCase: ToOwned {
+    /// Convert this type to snek case.
+    fn to_snek_case(&self) -> Self::Owned;
+}
+
+impl<T: ?Sized + ToSnakeCase> ToSnekCase for T {
+    fn to_snek_case(&self) -> Self::Owned {
+        self.to_snake_case()
+    }
+}
+
+impl ToSnakeCase for str {
+    fn to_snake_case(&self) -> String {
+        AsSnakeCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a snake case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsSnakeCase;
+///
+/// let sentence = "We carry a new world here, in our hearts.";
+/// assert_eq!(format!("{}", AsSnakeCase(sentence)), "we_carry_a_new_world_here_in_our_hearts");
+/// ```
+pub struct AsSnakeCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsSnakeCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), lowercase, |f| write!(f, "_"), f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToSnakeCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_snake_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "camel_case");
+    t!(test2: "This is Human case." => "this_is_human_case");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "mixed_up_camel_case_with_some_spaces");
+    t!(test4: "mixed_up_ snake_case with some _spaces" => "mixed_up_snake_case_with_some_spaces");
+    t!(test5: "kebab-case" => "kebab_case");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "shouty_snake_case");
+    t!(test7: "snake_case" => "snake_case");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "this_contains_all_kinds_of_word_boundaries");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baffle" => "xσxς_baffle");
+    t!(test10: "XMLHttpRequest" => "xml_http_request");
+    t!(test11: "FIELD_NAME11" => "field_name11");
+    t!(test12: "99BOTTLES" => "99bottles");
+    t!(test13: "FieldNamE11" => "field_nam_e11");
+
+    t!(test14: "abc123def456" => "abc123def456");
+    t!(test16: "abc123DEF456" => "abc123_def456");
+    t!(test17: "abc123Def456" => "abc123_def456");
+    t!(test18: "abc123DEf456" => "abc123_d_ef456");
+    t!(test19: "ABC123def456" => "abc123def456");
+    t!(test20: "ABC123DEF456" => "abc123def456");
+    t!(test21: "ABC123Def456" => "abc123_def456");
+    t!(test22: "ABC123DEf456" => "abc123d_ef456");
+    t!(test23: "ABC123dEEf456FOO" => "abc123d_e_ef456_foo");
+    t!(test24: "abcDEF" => "abc_def");
+    t!(test25: "ABcDE" => "a_bc_de");
+}
diff --git a/third_party/rust/heck/src/title.rs b/third_party/rust/heck/src/title.rs
new file mode 100644
index 0000000000..fdf175b733
--- /dev/null
+++ b/third_party/rust/heck/src/title.rs
@@ -0,0 +1,71 @@
+use std::fmt;
+
+use crate::{capitalize, transform};
+
+/// This trait defines a title case conversion.
+///
+/// In Title Case, word boundaries are indicated by spaces, and every word is
+/// capitalized.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToTitleCase;
+///
+/// let sentence = "We have always lived in slums and holes in the wall.";
+/// assert_eq!(sentence.to_title_case(), "We Have Always Lived In Slums And Holes In The Wall");
+/// ```
+pub trait ToTitleCase: ToOwned {
+    /// Convert this type to title case.
+    fn to_title_case(&self) -> Self::Owned;
+}
+
+impl ToTitleCase for str {
+    fn to_title_case(&self) -> String {
+        AsTitleCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a title case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsTitleCase;
+///
+/// let sentence = "We have always lived in slums and holes in the wall.";
+/// assert_eq!(format!("{}", AsTitleCase(sentence)), "We Have Always Lived In Slums And Holes In The Wall");
+/// ```
+pub struct AsTitleCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsTitleCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), capitalize, |f| write!(f, " "), f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToTitleCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_title_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "Camel Case");
+    t!(test2: "This is Human case." => "This Is Human Case");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "Mixed Up Camel Case With Some Spaces");
+    t!(test4: "mixed_up_ snake_case, with some _spaces" => "Mixed Up Snake Case With Some Spaces");
+    t!(test5: "kebab-case" => "Kebab Case");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "Shouty Snake Case");
+    t!(test7: "snake_case" => "Snake Case");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "This Contains All Kinds Of Word Boundaries");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baffle" => "Xσxς Baffle");
+    t!(test10: "XMLHttpRequest" => "Xml Http Request");
+}
diff --git a/third_party/rust/heck/src/train.rs b/third_party/rust/heck/src/train.rs
new file mode 100644
index 0000000000..04dd6a9965
--- /dev/null
+++ b/third_party/rust/heck/src/train.rs
@@ -0,0 +1,85 @@
+use std::fmt;
+
+use crate::{capitalize, transform};
+
+/// This trait defines a train case conversion.
+///
+/// In Train-Case, word boundaries are indicated by hyphens and words start
+/// with Capital Letters.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToTrainCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(sentence.to_train_case(), "We-Are-Going-To-Inherit-The-Earth");
+/// ```
+pub trait ToTrainCase: ToOwned {
+    /// Convert this type to Train-Case.
+    fn to_train_case(&self) -> Self::Owned;
+}
+
+impl ToTrainCase for str {
+    fn to_train_case(&self) -> Self::Owned {
+        AsTrainCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a train case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsTrainCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(format!("{}", AsTrainCase(sentence)), "We-Are-Going-To-Inherit-The-Earth");
+/// ```
+pub struct AsTrainCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsTrainCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), capitalize, |f| write!(f, "-"), f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToTrainCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_train_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "Camel-Case");
+    t!(test2: "This is Human case." => "This-Is-Human-Case");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "Mixed-Up-Camel-Case-With-Some-Spaces");
+    t!(test4: "mixed_up_ snake_case with some _spaces" => "Mixed-Up-Snake-Case-With-Some-Spaces");
+    t!(test5: "kebab-case" => "Kebab-Case");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "Shouty-Snake-Case");
+    t!(test7: "snake_case" => "Snake-Case");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "This-Contains-All-Kinds-Of-Word-Boundaries");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baffle" => "Xσxς-Baffle");
+    t!(test10: "XMLHttpRequest" => "Xml-Http-Request");
+    t!(test11: "FIELD_NAME11" => "Field-Name11");
+    t!(test12: "99BOTTLES" => "99bottles");
+    t!(test13: "FieldNamE11" => "Field-Nam-E11");
+    t!(test14: "abc123def456" => "Abc123def456");
+    t!(test16: "abc123DEF456" => "Abc123-Def456");
+    t!(test17: "abc123Def456" => "Abc123-Def456");
+    t!(test18: "abc123DEf456" => "Abc123-D-Ef456");
+    t!(test19: "ABC123def456" => "Abc123def456");
+    t!(test20: "ABC123DEF456" => "Abc123def456");
+    t!(test21: "ABC123Def456" => "Abc123-Def456");
+    t!(test22: "ABC123DEf456" => "Abc123d-Ef456");
+    t!(test23: "ABC123dEEf456FOO" => "Abc123d-E-Ef456-Foo");
+    t!(test24: "abcDEF" => "Abc-Def");
+    t!(test25: "ABcDE" => "A-Bc-De");
+}
diff --git a/third_party/rust/heck/src/upper_camel.rs b/third_party/rust/heck/src/upper_camel.rs
new file mode 100644
index 0000000000..70bf4ac70a
--- /dev/null
+++ b/third_party/rust/heck/src/upper_camel.rs
@@ -0,0 +1,84 @@
+use std::fmt;
+
+use crate::{capitalize, transform};
+
+/// This trait defines an upper camel case conversion.
+///
+/// In UpperCamelCase, word boundaries are indicated by capital letters,
+/// including the first word.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToUpperCamelCase;
+///
+/// let sentence = "We are not in the least afraid of ruins.";
+/// assert_eq!(sentence.to_upper_camel_case(), "WeAreNotInTheLeastAfraidOfRuins");
+/// ```
+pub trait ToUpperCamelCase: ToOwned {
+    /// Convert this type to upper camel case.
+    fn to_upper_camel_case(&self) -> Self::Owned;
+}
+
+impl ToUpperCamelCase for str {
+    fn to_upper_camel_case(&self) -> String {
+        AsUpperCamelCase(self).to_string()
+    }
+}
+
+/// ToPascalCase is an alias for ToUpperCamelCase. See ToUpperCamelCase for more
+/// documentation.
+pub trait ToPascalCase: ToOwned {
+    /// Convert this type to upper camel case.
+    fn to_pascal_case(&self) -> Self::Owned;
+}
+
+impl<T: ?Sized + ToUpperCamelCase> ToPascalCase for T {
+    fn to_pascal_case(&self) -> Self::Owned {
+        self.to_upper_camel_case()
+    }
+}
+
+/// This wrapper performs a upper camel case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsUpperCamelCase;
+///
+/// let sentence = "We are not in the least afraid of ruins.";
+/// assert_eq!(format!("{}", AsUpperCamelCase(sentence)), "WeAreNotInTheLeastAfraidOfRuins");
+/// ```
+pub struct AsUpperCamelCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsUpperCamelCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), capitalize, |_| Ok(()), f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToUpperCamelCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_upper_camel_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "CamelCase");
+    t!(test2: "This is Human case." => "ThisIsHumanCase");
+    t!(test3: "MixedUP_CamelCase, with some Spaces" => "MixedUpCamelCaseWithSomeSpaces");
+    t!(test4: "mixed_up_ snake_case, with some _spaces" => "MixedUpSnakeCaseWithSomeSpaces");
+    t!(test5: "kebab-case" => "KebabCase");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "ShoutySnakeCase");
+    t!(test7: "snake_case" => "SnakeCase");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "ThisContainsAllKindsOfWordBoundaries");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baffle" => "XσxςBaffle");
+    t!(test10: "XMLHttpRequest" => "XmlHttpRequest");
+}