vendor/unicode-script/src/lib.rs - toolchain/rustc - Git at Google

 //! This crate exposes the Unicode `Script` and `Script_Extension`
 //! properties from [UAX #24](http://www.unicode.org/reports/tr24/)

 #![cfg_attr(not(test), no_std)]
 #![cfg_attr(feature = "bench", feature(test))]

 #[rustfmt::skip]
 mod tables;

 use core::convert::TryFrom;
 use core::fmt;
 use core::u64;
 pub use tables::script_extensions;
 use tables::{get_script, get_script_extension, NEXT_SCRIPT};
 pub use tables::{Script, UNICODE_VERSION};

 impl Script {
     /// Get the full name of a script
     pub fn full_name(self) -> &'static str {
         self.inner_full_name()
     }

     /// Get the four-character short name of a script
     pub fn short_name(self) -> &'static str {
         self.inner_short_name()
     }

     /// Is this script "Recommended" according to
     /// [UAX #31](www.unicode.org/reports/tr31/#Table_Recommended_Scripts)?
     pub fn is_recommended(self) -> bool {
         use Script::*;
         match self {
             Common | Inherited | Arabic | Armenian | Bengali | Bopomofo | Cyrillic | Devanagari
             | Ethiopic | Georgian | Greek | Gujarati | Gurmukhi | Han | Hangul | Hebrew
             | Hiragana | Kannada | Katakana | Khmer | Lao | Latin | Malayalam | Myanmar | Oriya
             | Sinhala | Tamil | Telugu | Thaana | Thai | Tibetan => true,
             _ => false,
         }
     }
 }

 impl From<Script> for ScriptExtension {
     fn from(script: Script) -> Self {
         if script == Script::Common {
             ScriptExtension::new_common()
         } else if script == Script::Inherited {
             ScriptExtension::new_inherited()
         } else if script == Script::Unknown {
             ScriptExtension::new_unknown()
         } else {
             let mut first = 0;
             let mut second = 0;
             let mut third = 0;
             let bit = script as u8;
             // Find out which field it's in, and set the appropriate bit there
             if bit < 64 {
                 first = 1 << bit as u64;
             } else if bit < 128 {
                 // offset by 64 since `bit` is an absolute number,
                 // not relative to the chunk
                 second = 1 << (bit - 64) as u64;
             } else {
                 third = 1 << (bit - 128) as u32;
             }
             ScriptExtension::new(first, second, third)
         }
     }
 }

 impl TryFrom<ScriptExtension> for Script {
     type Error = ();
     fn try_from(ext: ScriptExtension) -> Result<Self, ()> {
         if ext.is_common_or_inherited() {
             if ext.common {
                 Ok(Script::Common)
             } else {
                 Ok(Script::Inherited)
             }
         } else if ext.is_empty() {
             Ok(Script::Unknown)
         } else {
             // filled elements will have set ones
             let fo = ext.first.count_ones();
             let so = ext.second.count_ones();
             let to = ext.third.count_ones();
             // only one bit set, in the first chunk
             if fo == 1 && so == 0 && to == 0 {
                 // use trailing_zeroes() to figure out which bit it is
                 Ok(Script::for_integer(ext.first.trailing_zeros() as u8))
             // only one bit set, in the second chunk
             } else if fo == 0 && so == 1 && to == 0 {
                 Ok(Script::for_integer(64 + ext.second.trailing_zeros() as u8))
             // only one bit set, in the third chunk
             } else if fo == 0 && so == 0 && to == 1 {
                 Ok(Script::for_integer(128 + ext.third.trailing_zeros() as u8))
             } else {
                 Err(())
             }
         }
     }
 }

 impl Default for Script {
     fn default() -> Self {
         Script::Common
     }
 }

 impl From<char> for Script {
     fn from(o: char) -> Self {
         o.script()
     }
 }

 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
 #[non_exhaustive]
 /// A value for the `Script_Extension` property
 ///
 /// [`ScriptExtension`] is one or more [`Script`]
 ///
 /// This is essentially an optimized version of `Vec<Script>` that uses bitfields
 pub struct ScriptExtension {
     // A bitset for the first 64 scripts
     first: u64,
     // A bitset for the scripts 65-128
     second: u64,
     // A bitset for scripts after 128
     third: u32,
     // Both Common and Inherited are represented by all used bits being set,
     // this flag lets us distinguish the two.
     common: bool,
 }

 impl ScriptExtension {
     // We don't use the complete u32 of `third`, so the "all" value is not just u32::MAX
     // Instead, we take the number of the next (unused) script bit, subtract 128 to bring
     // it in the range of `third`, create a u32 with just that bit set, and subtract 1
     // to create one with all the lower bits set.
     const THIRD_MAX: u32 = ((1 << (NEXT_SCRIPT - 128)) - 1);

     pub(crate) const fn new(first: u64, second: u64, third: u32) -> Self {
         ScriptExtension {
             first,
             second,
             third,
             common: false,
         }
     }

     pub(crate) const fn new_common() -> Self {
         ScriptExtension {
             first: u64::MAX,
             second: u64::MAX,
             third: Self::THIRD_MAX,
             common: true,
         }
     }

     pub(crate) const fn new_inherited() -> Self {
         ScriptExtension {
             first: u64::MAX,
             second: u64::MAX,
             third: Self::THIRD_MAX,
             common: false,
         }
     }

     pub(crate) const fn new_unknown() -> Self {
         ScriptExtension {
             first: 0,
             second: 0,
             third: 0,
             common: false,
         }
     }

     const fn is_common_or_inherited(self) -> bool {
         (self.first == u64::MAX) & (self.second == u64::MAX) & (self.third == Self::THIRD_MAX)
     }

     /// Checks if the script extension is Common
     pub const fn is_common(self) -> bool {
         self.is_common_or_inherited() & self.common
     }

     /// Checks if the script extension is Inherited
     pub const fn is_inherited(self) -> bool {
         self.is_common_or_inherited() & !self.common
     }

     /// Checks if the script extension is empty (unknown)
     pub const fn is_empty(self) -> bool {
         (self.first == 0) & (self.second == 0) & (self.third == 0)
     }

     /// Returns the number of scripts in the script extension
     pub fn len(self) -> usize {
         if self.is_common_or_inherited() {
             1
         } else {
             (self.first.count_ones() + self.second.count_ones() + self.third.count_ones()) as usize
         }
     }

     /// Intersect this `ScriptExtension` with another `ScriptExtension`. Produces `Unknown` if things
     /// do not intersect. This is equivalent to [`ScriptExtension::intersection`] but it stores the result
     /// in `self`
     ///
     /// "Common" (`Zyyy`) and "Inherited" (`Zinh`) are considered as intersecting
     /// everything, the intersection of `Common` and `Inherited` is `Inherited`
     pub fn intersect_with(&mut self, other: Self) {
         *self = self.intersection(other)
     }

     /// Find the intersection between two ScriptExtensions. Returns Unknown if things
     /// do not intersect.
     ///
     /// "Common" (`Zyyy`) and "Inherited" (`Zinh`) are considered as intersecting
     /// everything, the intersection of `Common` and `Inherited` is `Inherited`
     pub const fn intersection(self, other: Self) -> Self {
         let first = self.first & other.first;
         let second = self.second & other.second;
         let third = self.third & other.third;
         let common = self.common & other.common;
         ScriptExtension {
             first,
             second,
             third,
             common,
         }
     }

     /// Find the union between two ScriptExtensions.
     ///
     /// "Common" (`Zyyy`) and "Inherited" (`Zinh`) are considered as intersecting
     /// everything, the union of `Common` and `Inherited` is `Common`
     pub const fn union(self, other: Self) -> Self {
         let first = self.first | other.first;
         let second = self.second | other.second;
         let third = self.third | other.third;
         let common = self.common | other.common;
         ScriptExtension {
             first,
             second,
             third,
             common,
         }
     }

     /// Check if this ScriptExtension contains the given script
     ///
     /// Should be used with specific scripts only, this will
     /// return `true` if `self` is not `Unknown` and `script` is
     /// `Common` or `Inherited`
     pub fn contains_script(self, script: Script) -> bool {
         !self.intersection(script.into()).is_empty()
     }

     /// Get the intersection of script extensions of all characters
     /// in a string.
     pub fn for_str(x: &str) -> Self {
         let mut ext = ScriptExtension::default();
         for ch in x.chars() {
             ext.intersect_with(ch.into());
         }
         ext
     }

     /// Iterate over the scripts in this script extension
     ///
     /// Will never yield Script::Unknown
     pub fn iter(self) -> ScriptIterator {
         ScriptIterator { ext: self }
     }
 }

 impl Default for ScriptExtension {
     fn default() -> Self {
         ScriptExtension::new_common()
     }
 }

 impl From<char> for ScriptExtension {
     fn from(o: char) -> Self {
         o.script_extension()
     }
 }

 impl From<&'_ str> for ScriptExtension {
     fn from(o: &'_ str) -> Self {
         Self::for_str(o)
     }
 }

 impl fmt::Debug for ScriptExtension {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "ScriptExtension(")?;
         if self.is_common() {
             write!(f, "Common")?;
         } else if self.is_inherited() {
             write!(f, "Inherited")?;
         } else if self.is_empty() {
             write!(f, "Unknown")?;
         } else {
             let mut first = true;
             for script in self.iter() {
                 if !first {
                     write!(f, " + ")?;
                     first = false;
                 }
                 script.full_name().fmt(f)?;
             }
         }
         write!(f, ")")
     }
 }

 /// Extension trait on `char` for calculating script properties
 pub trait UnicodeScript {
     /// Get the script for a given character
     fn script(&self) -> Script;
     /// Get the Script_Extension for a given character
     fn script_extension(&self) -> ScriptExtension;
 }

 impl UnicodeScript for char {
     fn script(&self) -> Script {
         get_script(*self).unwrap_or(Script::Unknown)
     }

     fn script_extension(&self) -> ScriptExtension {
         get_script_extension(*self).unwrap_or_else(|| self.script().into())
     }
 }

 /// Iterator over scripts in a [ScriptExtension].
 ///
 /// Can be obtained ia [ScriptExtension::iter()]
 pub struct ScriptIterator {
     ext: ScriptExtension,
 }

 impl Iterator for ScriptIterator {
     type Item = Script;

     fn next(&mut self) -> Option<Script> {
         if self.ext.is_common_or_inherited() {
             let common = self.ext.common;
             self.ext = ScriptExtension::new_unknown();
             if common {
                 Some(Script::Common)
             } else {
                 Some(Script::Inherited)
             }
         // Are there bits left in the first chunk?
         } else if self.ext.first != 0 {
             // Find the next bit
             let bit = self.ext.first.trailing_zeros();
             // unset just that bit
             self.ext.first &= !(1 << bit);
             Some(Script::for_integer(bit as u8))
         // Are there bits left in the second chunk?
         } else if self.ext.second != 0 {
             let bit = self.ext.second.trailing_zeros();
             self.ext.second &= !(1 << bit);
             Some(Script::for_integer(64 + bit as u8))
         // Are there bits left in the third chunk?
         } else if self.ext.third != 0 {
             let bit = self.ext.third.trailing_zeros();
             self.ext.third &= !(1 << bit);
             Some(Script::for_integer(128 + bit as u8))
         } else {
             // Script::Unknown
             None
         }
     }
 }

 #[cfg(test)]
 mod tests {
     use crate::*;
     use std::collections::HashSet;
     use std::convert::TryInto;

     #[cfg(feature = "bench")]
     use test::bench::Bencher;
     #[cfg(feature = "bench")]
     extern crate test;

     #[test]
     fn test_conversion() {
         let mut seen_scripts = HashSet::new();
         let mut seen_exts = HashSet::new();
         for bit in 0..NEXT_SCRIPT {
             let script = Script::for_integer(bit);
             let ext = script.into();
             if seen_scripts.contains(&script) {
                 panic!("Found script {:?} twice!", script)
             }
             if seen_exts.contains(&ext) {
                 panic!("Found extension {:?} twice!", ext)
             }
             seen_scripts.insert(script);
             seen_exts.insert(ext);
             assert_eq!(script as u8, bit);
             assert!(!ScriptExtension::new_common().intersection(ext).is_empty());
             assert!(!ScriptExtension::new_inherited()
                 .intersection(ext)
                 .is_empty());
             assert!(ScriptExtension::new_unknown().intersection(ext).is_empty());
             assert_eq!(ext.iter().collect::<Vec<_>>(), vec![script]);
             assert_eq!(Ok(script), ext.try_into());
         }
     }

     #[test]
     fn test_specific() {
         let s = "सवव मानवी व्यद्क् जन्मतःच स्वतींत्र आहेत व त्ाींना समान प्रवतष्ठा व समान अविकार आहेत. त्ाींना ववचारशद्क् व सवविे कबुद्द्धलाभलेली आहे. व त्ाींनी एकमेकाींशी बींिुत्वाचाभावनेने आचरण करावे.";
         let ext = ScriptExtension::for_str(s);
         assert_eq!(ext, script_extensions::DEVA);
         println!(
             "{:?}",
             script_extensions::DEVA_DOGR_GUJR_GURU_KHOJ_KTHI_MAHJ_MODI_SIND_TAKR_TIRH
         );
         println!(
             "{:?}",
             ext.intersection(
                 script_extensions::DEVA_DOGR_GUJR_GURU_KHOJ_KTHI_MAHJ_MODI_SIND_TAKR_TIRH
             )
         );
         assert!(!ext
             .intersection(script_extensions::DEVA_DOGR_GUJR_GURU_KHOJ_KTHI_MAHJ_MODI_SIND_TAKR_TIRH)
             .is_empty());

         let u = ext.union(Script::Dogra.into());
         assert_eq!(
             u.intersection(
                 script_extensions::DEVA_DOGR_GUJR_GURU_KHOJ_KTHI_MAHJ_MODI_SIND_TAKR_TIRH
             ),
             u
         );
     }

     #[test]
     fn test_specific_ext() {
         let ext = script_extensions::DEVA_DOGR_GUJR_GURU_KHOJ_KTHI_MAHJ_MODI_SIND_TAKR_TIRH;

         let all: HashSet<_> = ext.iter().collect();

         for bit in 0..NEXT_SCRIPT {
             let script = Script::for_integer(bit);

             if all.contains(&script) {
                 assert!(ext.contains_script(script))
             } else {
                 assert!(!ext.contains_script(script))
             }
         }

         assert!(ext.contains_script(Script::Devanagari));
         assert!(ext.contains_script(Script::Dogra));
         assert!(ext.contains_script(Script::Gujarati));
         assert!(ext.contains_script(Script::Gurmukhi));
         assert!(ext.contains_script(Script::Khojki));
         assert!(ext.contains_script(Script::Kaithi));
         assert!(ext.contains_script(Script::Mahajani));
         assert!(ext.contains_script(Script::Modi));
         assert!(ext.contains_script(Script::Khudawadi));
         assert!(ext.contains_script(Script::Takri));
         assert!(ext.contains_script(Script::Tirhuta));

         let scr: Result<Script, _> = ext.try_into();
         assert!(scr.is_err());
     }

     #[cfg(feature = "bench")]
     #[bench]
     fn bench_script_intersection(b: &mut Bencher) {
         b.iter(|| {
             let script = test::black_box(Script::Devanagari);
             let ext = test::black_box(script_extensions::BENG_DEVA_DOGR_GONG_GONM_GRAN_GUJR_GURU_KNDA_MAHJ_MLYM_NAND_ORYA_SIND_SINH_SYLO_TAKR_TAML_TELU_TIRH);
             test::black_box(ext.intersection(script.into()));
         })
     }

     #[cfg(feature = "bench")]
     #[bench]
     fn bench_ext_to_script(b: &mut Bencher) {
         let ext: ScriptExtension = Script::Devanagari.into();
         b.iter(|| {
             let ext = test::black_box(ext);
             let script: Result<Script, _> = ext.try_into();
             let _ = test::black_box(script);
         })
     }

     #[cfg(feature = "bench")]
     #[bench]
     fn bench_script_to_ext(b: &mut Bencher) {
         b.iter(|| {
             let script = test::black_box(Script::Devanagari);
             let ext: ScriptExtension = script.into();
             test::black_box(ext);
         })
     }

     #[cfg(feature = "bench")]
     #[bench]
     fn bench_ext_intersection(b: &mut Bencher) {
         b.iter(|| {
             let e1 = test::black_box(script_extensions::ARAB_ROHG_SYRC_THAA_YEZI);
             let e2 = test::black_box(script_extensions::BENG_DEVA_DOGR_GONG_GONM_GRAN_GUJR_GURU_KNDA_MAHJ_MLYM_NAND_ORYA_SIND_SINH_SYLO_TAKR_TAML_TELU_TIRH);
             test::black_box(e2.intersection(e1));
         })
     }

     #[cfg(feature = "bench")]
     #[bench]
     fn bench_to_vec(b: &mut Bencher) {
         b.iter(|| {
             let ext = test::black_box(script_extensions::BENG_DEVA_DOGR_GONG_GONM_GRAN_GUJR_GURU_KNDA_MAHJ_MLYM_NAND_ORYA_SIND_SINH_SYLO_TAKR_TAML_TELU_TIRH);
             test::black_box(ext.iter().collect::<Vec<_>>());
         })
     }

     #[cfg(feature = "bench")]
     #[bench]
     fn bench_string_ext(b: &mut Bencher) {
         b.iter(|| {
             let s = test::black_box("सवव मानवी व्यद्क् जन्मतःच स्वतींत्र आहेत व त्ाींना समान प्रवतष्ठा व समान अविकार आहेत. त्ाींना ववचारशद्क् व सवविे कबुद्द्धलाभलेली आहे. व त्ाींनी एकमेकाींशी बींिुत्वाचाभावनेने आचरण करावे.");
             test::black_box(ScriptExtension::for_str(s));
         })
     }
 }
	//! This crate exposes the Unicode `Script` and `Script_Extension`
	//! properties from [UAX #24](http://www.unicode.org/reports/tr24/)

	#![cfg_attr(not(test), no_std)]
	#![cfg_attr(feature = "bench", feature(test))]

	#[rustfmt::skip]
	mod tables;

	use core::convert::TryFrom;
	use core::fmt;
	use core::u64;
	pub use tables::script_extensions;
	use tables::{get_script, get_script_extension, NEXT_SCRIPT};
	pub use tables::{Script, UNICODE_VERSION};

	impl Script {
	/// Get the full name of a script
	pub fn full_name(self) -> &'static str {
	self.inner_full_name()
	}

	/// Get the four-character short name of a script
	pub fn short_name(self) -> &'static str {
	self.inner_short_name()
	}

	/// Is this script "Recommended" according to
	/// [UAX #31](www.unicode.org/reports/tr31/#Table_Recommended_Scripts)?
	pub fn is_recommended(self) -> bool {
	use Script::*;
	match self {
	Common \| Inherited \| Arabic \| Armenian \| Bengali \| Bopomofo \| Cyrillic \| Devanagari
	\| Ethiopic \| Georgian \| Greek \| Gujarati \| Gurmukhi \| Han \| Hangul \| Hebrew
	\| Hiragana \| Kannada \| Katakana \| Khmer \| Lao \| Latin \| Malayalam \| Myanmar \| Oriya
	\| Sinhala \| Tamil \| Telugu \| Thaana \| Thai \| Tibetan => true,
	_ => false,
	}
	}
	}

	impl From<Script> for ScriptExtension {
	fn from(script: Script) -> Self {
	if script == Script::Common {
	ScriptExtension::new_common()
	} else if script == Script::Inherited {
	ScriptExtension::new_inherited()
	} else if script == Script::Unknown {
	ScriptExtension::new_unknown()
	} else {
	let mut first = 0;
	let mut second = 0;
	let mut third = 0;
	let bit = script as u8;
	// Find out which field it's in, and set the appropriate bit there
	if bit < 64 {
	first = 1 << bit as u64;
	} else if bit < 128 {
	// offset by 64 since `bit` is an absolute number,
	// not relative to the chunk
	second = 1 << (bit - 64) as u64;
	} else {
	third = 1 << (bit - 128) as u32;
	}
	ScriptExtension::new(first, second, third)
	}
	}
	}

	impl TryFrom<ScriptExtension> for Script {
	type Error = ();
	fn try_from(ext: ScriptExtension) -> Result<Self, ()> {
	if ext.is_common_or_inherited() {
	if ext.common {
	Ok(Script::Common)
	} else {
	Ok(Script::Inherited)
	}
	} else if ext.is_empty() {
	Ok(Script::Unknown)
	} else {
	// filled elements will have set ones
	let fo = ext.first.count_ones();
	let so = ext.second.count_ones();
	let to = ext.third.count_ones();
	// only one bit set, in the first chunk
	if fo == 1 && so == 0 && to == 0 {
	// use trailing_zeroes() to figure out which bit it is
	Ok(Script::for_integer(ext.first.trailing_zeros() as u8))
	// only one bit set, in the second chunk
	} else if fo == 0 && so == 1 && to == 0 {
	Ok(Script::for_integer(64 + ext.second.trailing_zeros() as u8))
	// only one bit set, in the third chunk
	} else if fo == 0 && so == 0 && to == 1 {
	Ok(Script::for_integer(128 + ext.third.trailing_zeros() as u8))
	} else {
	Err(())
	}
	}
	}
	}

	impl Default for Script {
	fn default() -> Self {
	Script::Common
	}
	}

	impl From<char> for Script {
	fn from(o: char) -> Self {
	o.script()
	}
	}

	#[derive(Clone, Copy, PartialEq, Eq, Hash)]
	#[non_exhaustive]
	/// A value for the `Script_Extension` property
	///
	/// [`ScriptExtension`] is one or more [`Script`]
	///
	/// This is essentially an optimized version of `Vec<Script>` that uses bitfields
	pub struct ScriptExtension {
	// A bitset for the first 64 scripts
	first: u64,
	// A bitset for the scripts 65-128
	second: u64,
	// A bitset for scripts after 128
	third: u32,
	// Both Common and Inherited are represented by all used bits being set,
	// this flag lets us distinguish the two.
	common: bool,
	}

	impl ScriptExtension {
	// We don't use the complete u32 of `third`, so the "all" value is not just u32::MAX
	// Instead, we take the number of the next (unused) script bit, subtract 128 to bring
	// it in the range of `third`, create a u32 with just that bit set, and subtract 1
	// to create one with all the lower bits set.
	const THIRD_MAX: u32 = ((1 << (NEXT_SCRIPT - 128)) - 1);

	pub(crate) const fn new(first: u64, second: u64, third: u32) -> Self {
	ScriptExtension {
	first,
	second,
	third,
	common: false,
	}
	}

	pub(crate) const fn new_common() -> Self {
	ScriptExtension {
	first: u64::MAX,
	second: u64::MAX,
	third: Self::THIRD_MAX,
	common: true,
	}
	}

	pub(crate) const fn new_inherited() -> Self {
	ScriptExtension {
	first: u64::MAX,
	second: u64::MAX,
	third: Self::THIRD_MAX,
	common: false,
	}
	}

	pub(crate) const fn new_unknown() -> Self {
	ScriptExtension {
	first: 0,
	second: 0,
	third: 0,
	common: false,
	}
	}

	const fn is_common_or_inherited(self) -> bool {
	(self.first == u64::MAX) & (self.second == u64::MAX) & (self.third == Self::THIRD_MAX)
	}

	/// Checks if the script extension is Common
	pub const fn is_common(self) -> bool {
	self.is_common_or_inherited() & self.common
	}

	/// Checks if the script extension is Inherited
	pub const fn is_inherited(self) -> bool {
	self.is_common_or_inherited() & !self.common
	}

	/// Checks if the script extension is empty (unknown)
	pub const fn is_empty(self) -> bool {
	(self.first == 0) & (self.second == 0) & (self.third == 0)
	}

	/// Returns the number of scripts in the script extension
	pub fn len(self) -> usize {
	if self.is_common_or_inherited() {
	1
	} else {
	(self.first.count_ones() + self.second.count_ones() + self.third.count_ones()) as usize
	}
	}

	/// Intersect this `ScriptExtension` with another `ScriptExtension`. Produces `Unknown` if things
	/// do not intersect. This is equivalent to [`ScriptExtension::intersection`] but it stores the result
	/// in `self`
	///
	/// "Common" (`Zyyy`) and "Inherited" (`Zinh`) are considered as intersecting
	/// everything, the intersection of `Common` and `Inherited` is `Inherited`
	pub fn intersect_with(&mut self, other: Self) {
	*self = self.intersection(other)
	}

	/// Find the intersection between two ScriptExtensions. Returns Unknown if things
	/// do not intersect.
	///
	/// "Common" (`Zyyy`) and "Inherited" (`Zinh`) are considered as intersecting
	/// everything, the intersection of `Common` and `Inherited` is `Inherited`
	pub const fn intersection(self, other: Self) -> Self {
	let first = self.first & other.first;
	let second = self.second & other.second;
	let third = self.third & other.third;
	let common = self.common & other.common;
	ScriptExtension {
	first,
	second,
	third,
	common,
	}
	}

	/// Find the union between two ScriptExtensions.
	///
	/// "Common" (`Zyyy`) and "Inherited" (`Zinh`) are considered as intersecting
	/// everything, the union of `Common` and `Inherited` is `Common`
	pub const fn union(self, other: Self) -> Self {
	let first = self.first \| other.first;
	let second = self.second \| other.second;
	let third = self.third \| other.third;
	let common = self.common \| other.common;
	ScriptExtension {
	first,
	second,
	third,
	common,
	}
	}

	/// Check if this ScriptExtension contains the given script
	///
	/// Should be used with specific scripts only, this will
	/// return `true` if `self` is not `Unknown` and `script` is
	/// `Common` or `Inherited`
	pub fn contains_script(self, script: Script) -> bool {
	!self.intersection(script.into()).is_empty()
	}

	/// Get the intersection of script extensions of all characters
	/// in a string.
	pub fn for_str(x: &str) -> Self {
	let mut ext = ScriptExtension::default();
	for ch in x.chars() {
	ext.intersect_with(ch.into());
	}
	ext
	}

	/// Iterate over the scripts in this script extension
	///
	/// Will never yield Script::Unknown
	pub fn iter(self) -> ScriptIterator {
	ScriptIterator { ext: self }
	}
	}

	impl Default for ScriptExtension {
	fn default() -> Self {
	ScriptExtension::new_common()
	}
	}

	impl From<char> for ScriptExtension {
	fn from(o: char) -> Self {
	o.script_extension()
	}
	}

	impl From<&'_ str> for ScriptExtension {
	fn from(o: &'_ str) -> Self {
	Self::for_str(o)
	}
	}

	impl fmt::Debug for ScriptExtension {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
	write!(f, "ScriptExtension(")?;
	if self.is_common() {
	write!(f, "Common")?;
	} else if self.is_inherited() {
	write!(f, "Inherited")?;
	} else if self.is_empty() {
	write!(f, "Unknown")?;
	} else {
	let mut first = true;
	for script in self.iter() {
	if !first {
	write!(f, " + ")?;
	first = false;
	}
	script.full_name().fmt(f)?;
	}
	}
	write!(f, ")")
	}
	}

	/// Extension trait on `char` for calculating script properties
	pub trait UnicodeScript {
	/// Get the script for a given character
	fn script(&self) -> Script;
	/// Get the Script_Extension for a given character
	fn script_extension(&self) -> ScriptExtension;
	}

	impl UnicodeScript for char {
	fn script(&self) -> Script {
	get_script(*self).unwrap_or(Script::Unknown)
	}

	fn script_extension(&self) -> ScriptExtension {
	get_script_extension(*self).unwrap_or_else(\|\| self.script().into())
	}
	}

	/// Iterator over scripts in a [ScriptExtension].
	///
	/// Can be obtained ia [ScriptExtension::iter()]
	pub struct ScriptIterator {
	ext: ScriptExtension,
	}

	impl Iterator for ScriptIterator {
	type Item = Script;

	fn next(&mut self) -> Option<Script> {
	if self.ext.is_common_or_inherited() {
	let common = self.ext.common;
	self.ext = ScriptExtension::new_unknown();
	if common {
	Some(Script::Common)
	} else {
	Some(Script::Inherited)
	}
	// Are there bits left in the first chunk?
	} else if self.ext.first != 0 {
	// Find the next bit
	let bit = self.ext.first.trailing_zeros();
	// unset just that bit
	self.ext.first &= !(1 << bit);
	Some(Script::for_integer(bit as u8))
	// Are there bits left in the second chunk?
	} else if self.ext.second != 0 {
	let bit = self.ext.second.trailing_zeros();
	self.ext.second &= !(1 << bit);
	Some(Script::for_integer(64 + bit as u8))
	// Are there bits left in the third chunk?
	} else if self.ext.third != 0 {
	let bit = self.ext.third.trailing_zeros();
	self.ext.third &= !(1 << bit);
	Some(Script::for_integer(128 + bit as u8))
	} else {
	// Script::Unknown
	None
	}
	}
	}

	#[cfg(test)]
	mod tests {
	use crate::*;
	use std::collections::HashSet;
	use std::convert::TryInto;

	#[cfg(feature = "bench")]
	use test::bench::Bencher;
	#[cfg(feature = "bench")]
	extern crate test;

	#[test]
	fn test_conversion() {
	let mut seen_scripts = HashSet::new();
	let mut seen_exts = HashSet::new();
	for bit in 0..NEXT_SCRIPT {
	let script = Script::for_integer(bit);
	let ext = script.into();
	if seen_scripts.contains(&script) {
	panic!("Found script {:?} twice!", script)
	}
	if seen_exts.contains(&ext) {
	panic!("Found extension {:?} twice!", ext)
	}
	seen_scripts.insert(script);
	seen_exts.insert(ext);
	assert_eq!(script as u8, bit);
	assert!(!ScriptExtension::new_common().intersection(ext).is_empty());
	assert!(!ScriptExtension::new_inherited()
	.intersection(ext)
	.is_empty());
	assert!(ScriptExtension::new_unknown().intersection(ext).is_empty());
	assert_eq!(ext.iter().collect::<Vec<_>>(), vec![script]);
	assert_eq!(Ok(script), ext.try_into());
	}
	}

	#[test]
	fn test_specific() {
	let s = "सवव मानवी व्यद्क् जन्मतःच स्वतींत्र आहेत व त्ाींना समान प्रवतष्ठा व समान अविकार आहेत. त्ाींना ववचारशद्क् व सवविे कबुद्द्धलाभलेली आहे. व त्ाींनी एकमेकाींशी बींिुत्वाचाभावनेने आचरण करावे.";
	let ext = ScriptExtension::for_str(s);
	assert_eq!(ext, script_extensions::DEVA);
	println!(
	"{:?}",
	script_extensions::DEVA_DOGR_GUJR_GURU_KHOJ_KTHI_MAHJ_MODI_SIND_TAKR_TIRH
	);
	println!(
	"{:?}",
	ext.intersection(
	script_extensions::DEVA_DOGR_GUJR_GURU_KHOJ_KTHI_MAHJ_MODI_SIND_TAKR_TIRH
	)
	);
	assert!(!ext
	.intersection(script_extensions::DEVA_DOGR_GUJR_GURU_KHOJ_KTHI_MAHJ_MODI_SIND_TAKR_TIRH)
	.is_empty());

	let u = ext.union(Script::Dogra.into());
	assert_eq!(
	u.intersection(
	script_extensions::DEVA_DOGR_GUJR_GURU_KHOJ_KTHI_MAHJ_MODI_SIND_TAKR_TIRH
	),
	u
	);
	}

	#[test]
	fn test_specific_ext() {
	let ext = script_extensions::DEVA_DOGR_GUJR_GURU_KHOJ_KTHI_MAHJ_MODI_SIND_TAKR_TIRH;

	let all: HashSet<_> = ext.iter().collect();

	for bit in 0..NEXT_SCRIPT {
	let script = Script::for_integer(bit);

	if all.contains(&script) {
	assert!(ext.contains_script(script))
	} else {
	assert!(!ext.contains_script(script))
	}
	}

	assert!(ext.contains_script(Script::Devanagari));
	assert!(ext.contains_script(Script::Dogra));
	assert!(ext.contains_script(Script::Gujarati));
	assert!(ext.contains_script(Script::Gurmukhi));
	assert!(ext.contains_script(Script::Khojki));
	assert!(ext.contains_script(Script::Kaithi));
	assert!(ext.contains_script(Script::Mahajani));
	assert!(ext.contains_script(Script::Modi));
	assert!(ext.contains_script(Script::Khudawadi));
	assert!(ext.contains_script(Script::Takri));
	assert!(ext.contains_script(Script::Tirhuta));

	let scr: Result<Script, _> = ext.try_into();
	assert!(scr.is_err());
	}

	#[cfg(feature = "bench")]
	#[bench]
	fn bench_script_intersection(b: &mut Bencher) {
	b.iter(\|\| {
	let script = test::black_box(Script::Devanagari);
	let ext = test::black_box(script_extensions::BENG_DEVA_DOGR_GONG_GONM_GRAN_GUJR_GURU_KNDA_MAHJ_MLYM_NAND_ORYA_SIND_SINH_SYLO_TAKR_TAML_TELU_TIRH);
	test::black_box(ext.intersection(script.into()));
	})
	}

	#[cfg(feature = "bench")]
	#[bench]
	fn bench_ext_to_script(b: &mut Bencher) {
	let ext: ScriptExtension = Script::Devanagari.into();
	b.iter(\|\| {
	let ext = test::black_box(ext);
	let script: Result<Script, _> = ext.try_into();
	let _ = test::black_box(script);
	})
	}

	#[cfg(feature = "bench")]
	#[bench]
	fn bench_script_to_ext(b: &mut Bencher) {
	b.iter(\|\| {
	let script = test::black_box(Script::Devanagari);
	let ext: ScriptExtension = script.into();
	test::black_box(ext);
	})
	}

	#[cfg(feature = "bench")]
	#[bench]
	fn bench_ext_intersection(b: &mut Bencher) {
	b.iter(\|\| {
	let e1 = test::black_box(script_extensions::ARAB_ROHG_SYRC_THAA_YEZI);
	let e2 = test::black_box(script_extensions::BENG_DEVA_DOGR_GONG_GONM_GRAN_GUJR_GURU_KNDA_MAHJ_MLYM_NAND_ORYA_SIND_SINH_SYLO_TAKR_TAML_TELU_TIRH);
	test::black_box(e2.intersection(e1));
	})
	}

	#[cfg(feature = "bench")]
	#[bench]
	fn bench_to_vec(b: &mut Bencher) {
	b.iter(\|\| {
	let ext = test::black_box(script_extensions::BENG_DEVA_DOGR_GONG_GONM_GRAN_GUJR_GURU_KNDA_MAHJ_MLYM_NAND_ORYA_SIND_SINH_SYLO_TAKR_TAML_TELU_TIRH);
	test::black_box(ext.iter().collect::<Vec<_>>());
	})
	}

	#[cfg(feature = "bench")]
	#[bench]
	fn bench_string_ext(b: &mut Bencher) {
	b.iter(\|\| {
	let s = test::black_box("सवव मानवी व्यद्क् जन्मतःच स्वतींत्र आहेत व त्ाींना समान प्रवतष्ठा व समान अविकार आहेत. त्ाींना ववचारशद्क् व सवविे कबुद्द्धलाभलेली आहे. व त्ाींनी एकमेकाींशी बींिुत्वाचाभावनेने आचरण करावे.");
	test::black_box(ScriptExtension::for_str(s));
	})
	}
	}