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Diffstat (limited to 'third_party/rust/regex-syntax/src/unicode.rs')
| -rw-r--r-- | third_party/rust/regex-syntax/src/unicode.rs | 1001 |
1 files changed, 1001 insertions, 0 deletions
diff --git a/third_party/rust/regex-syntax/src/unicode.rs b/third_party/rust/regex-syntax/src/unicode.rs new file mode 100644 index 0000000000..8194d7f55b --- /dev/null +++ b/third_party/rust/regex-syntax/src/unicode.rs @@ -0,0 +1,1001 @@ +use std::error; +use std::fmt; +use std::result; + +use crate::hir; + +/// A type alias for errors specific to Unicode handling of classes. +pub type Result<T> = result::Result<T, Error>; + +/// An inclusive range of codepoints from a generated file (hence the static +/// lifetime). +type Range = &'static [(char, char)]; + +/// An error that occurs when dealing with Unicode. +/// +/// We don't impl the Error trait here because these always get converted +/// into other public errors. (This error type isn't exported.) +#[derive(Debug)] +pub enum Error { + PropertyNotFound, + PropertyValueNotFound, + // Not used when unicode-perl is enabled. + #[allow(dead_code)] + PerlClassNotFound, +} + +/// A type alias for errors specific to Unicode case folding. +pub type FoldResult<T> = result::Result<T, CaseFoldError>; + +/// An error that occurs when Unicode-aware simple case folding fails. +/// +/// This error can occur when the case mapping tables necessary for Unicode +/// aware case folding are unavailable. This only occurs when the +/// `unicode-case` feature is disabled. (The feature is enabled by default.) +#[derive(Debug)] +pub struct CaseFoldError(()); + +impl error::Error for CaseFoldError {} + +impl fmt::Display for CaseFoldError { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!( + f, + "Unicode-aware case folding is not available \ + (probably because the unicode-case feature is not enabled)" + ) + } +} + +/// An error that occurs when the Unicode-aware `\w` class is unavailable. +/// +/// This error can occur when the data tables necessary for the Unicode aware +/// Perl character class `\w` are unavailable. This only occurs when the +/// `unicode-perl` feature is disabled. (The feature is enabled by default.) +#[derive(Debug)] +pub struct UnicodeWordError(()); + +impl error::Error for UnicodeWordError {} + +impl fmt::Display for UnicodeWordError { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!( + f, + "Unicode-aware \\w class is not available \ + (probably because the unicode-perl feature is not enabled)" + ) + } +} + +/// Return an iterator over the equivalence class of simple case mappings +/// for the given codepoint. The equivalence class does not include the +/// given codepoint. +/// +/// If the equivalence class is empty, then this returns the next scalar +/// value that has a non-empty equivalence class, if it exists. If no such +/// scalar value exists, then `None` is returned. The point of this behavior +/// is to permit callers to avoid calling `simple_fold` more than they need +/// to, since there is some cost to fetching the equivalence class. +/// +/// This returns an error if the Unicode case folding tables are not available. +pub fn simple_fold( + c: char, +) -> FoldResult<result::Result<impl Iterator<Item = char>, Option<char>>> { + #[cfg(not(feature = "unicode-case"))] + fn imp( + _: char, + ) -> FoldResult<result::Result<impl Iterator<Item = char>, Option<char>>> + { + use std::option::IntoIter; + Err::<result::Result<IntoIter<char>, _>, _>(CaseFoldError(())) + } + + #[cfg(feature = "unicode-case")] + fn imp( + c: char, + ) -> FoldResult<result::Result<impl Iterator<Item = char>, Option<char>>> + { + use crate::unicode_tables::case_folding_simple::CASE_FOLDING_SIMPLE; + + Ok(CASE_FOLDING_SIMPLE + .binary_search_by_key(&c, |&(c1, _)| c1) + .map(|i| CASE_FOLDING_SIMPLE[i].1.iter().copied()) + .map_err(|i| { + if i >= CASE_FOLDING_SIMPLE.len() { + None + } else { + Some(CASE_FOLDING_SIMPLE[i].0) + } + })) + } + + imp(c) +} + +/// Returns true if and only if the given (inclusive) range contains at least +/// one Unicode scalar value that has a non-empty non-trivial simple case +/// mapping. +/// +/// This function panics if `end < start`. +/// +/// This returns an error if the Unicode case folding tables are not available. +pub fn contains_simple_case_mapping( + start: char, + end: char, +) -> FoldResult<bool> { + #[cfg(not(feature = "unicode-case"))] + fn imp(_: char, _: char) -> FoldResult<bool> { + Err(CaseFoldError(())) + } + + #[cfg(feature = "unicode-case")] + fn imp(start: char, end: char) -> FoldResult<bool> { + use crate::unicode_tables::case_folding_simple::CASE_FOLDING_SIMPLE; + use std::cmp::Ordering; + + assert!(start <= end); + Ok(CASE_FOLDING_SIMPLE + .binary_search_by(|&(c, _)| { + if start <= c && c <= end { + Ordering::Equal + } else if c > end { + Ordering::Greater + } else { + Ordering::Less + } + }) + .is_ok()) + } + + imp(start, end) +} + +/// A query for finding a character class defined by Unicode. This supports +/// either use of a property name directly, or lookup by property value. The +/// former generally refers to Binary properties (see UTS#44, Table 8), but +/// as a special exception (see UTS#18, Section 1.2) both general categories +/// (an enumeration) and scripts (a catalog) are supported as if each of their +/// possible values were a binary property. +/// +/// In all circumstances, property names and values are normalized and +/// canonicalized. That is, `GC == gc == GeneralCategory == general_category`. +/// +/// The lifetime `'a` refers to the shorter of the lifetimes of property name +/// and property value. +#[derive(Debug)] +pub enum ClassQuery<'a> { + /// Return a class corresponding to a Unicode binary property, named by + /// a single letter. + OneLetter(char), + /// Return a class corresponding to a Unicode binary property. + /// + /// Note that, by special exception (see UTS#18, Section 1.2), both + /// general category values and script values are permitted here as if + /// they were a binary property. + Binary(&'a str), + /// Return a class corresponding to all codepoints whose property + /// (identified by `property_name`) corresponds to the given value + /// (identified by `property_value`). + ByValue { + /// A property name. + property_name: &'a str, + /// A property value. + property_value: &'a str, + }, +} + +impl<'a> ClassQuery<'a> { + fn canonicalize(&self) -> Result<CanonicalClassQuery> { + match *self { + ClassQuery::OneLetter(c) => self.canonical_binary(&c.to_string()), + ClassQuery::Binary(name) => self.canonical_binary(name), + ClassQuery::ByValue { property_name, property_value } => { + let property_name = symbolic_name_normalize(property_name); + let property_value = symbolic_name_normalize(property_value); + + let canon_name = match canonical_prop(&property_name)? { + None => return Err(Error::PropertyNotFound), + Some(canon_name) => canon_name, + }; + Ok(match canon_name { + "General_Category" => { + let canon = match canonical_gencat(&property_value)? { + None => return Err(Error::PropertyValueNotFound), + Some(canon) => canon, + }; + CanonicalClassQuery::GeneralCategory(canon) + } + "Script" => { + let canon = match canonical_script(&property_value)? { + None => return Err(Error::PropertyValueNotFound), + Some(canon) => canon, + }; + CanonicalClassQuery::Script(canon) + } + _ => { + let vals = match property_values(canon_name)? { + None => return Err(Error::PropertyValueNotFound), + Some(vals) => vals, + }; + let canon_val = + match canonical_value(vals, &property_value) { + None => { + return Err(Error::PropertyValueNotFound) + } + Some(canon_val) => canon_val, + }; + CanonicalClassQuery::ByValue { + property_name: canon_name, + property_value: canon_val, + } + } + }) + } + } + } + + fn canonical_binary(&self, name: &str) -> Result<CanonicalClassQuery> { + let norm = symbolic_name_normalize(name); + + // This is a special case where 'cf' refers to the 'Format' general + // category, but where the 'cf' abbreviation is also an abbreviation + // for the 'Case_Folding' property. But we want to treat it as + // a general category. (Currently, we don't even support the + // 'Case_Folding' property. But if we do in the future, users will be + // required to spell it out.) + if norm != "cf" { + if let Some(canon) = canonical_prop(&norm)? { + return Ok(CanonicalClassQuery::Binary(canon)); + } + } + if let Some(canon) = canonical_gencat(&norm)? { + return Ok(CanonicalClassQuery::GeneralCategory(canon)); + } + if let Some(canon) = canonical_script(&norm)? { + return Ok(CanonicalClassQuery::Script(canon)); + } + Err(Error::PropertyNotFound) + } +} + +/// Like ClassQuery, but its parameters have been canonicalized. This also +/// differentiates binary properties from flattened general categories and +/// scripts. +#[derive(Debug, Eq, PartialEq)] +enum CanonicalClassQuery { + /// The canonical binary property name. + Binary(&'static str), + /// The canonical general category name. + GeneralCategory(&'static str), + /// The canonical script name. + Script(&'static str), + /// An arbitrary association between property and value, both of which + /// have been canonicalized. + /// + /// Note that by construction, the property name of ByValue will never + /// be General_Category or Script. Those two cases are subsumed by the + /// eponymous variants. + ByValue { + /// The canonical property name. + property_name: &'static str, + /// The canonical property value. + property_value: &'static str, + }, +} + +/// Looks up a Unicode class given a query. If one doesn't exist, then +/// `None` is returned. +pub fn class(query: ClassQuery<'_>) -> Result<hir::ClassUnicode> { + use self::CanonicalClassQuery::*; + + match query.canonicalize()? { + Binary(name) => bool_property(name), + GeneralCategory(name) => gencat(name), + Script(name) => script(name), + ByValue { property_name: "Age", property_value } => { + let mut class = hir::ClassUnicode::empty(); + for set in ages(property_value)? { + class.union(&hir_class(set)); + } + Ok(class) + } + ByValue { property_name: "Script_Extensions", property_value } => { + script_extension(property_value) + } + ByValue { + property_name: "Grapheme_Cluster_Break", + property_value, + } => gcb(property_value), + ByValue { property_name: "Sentence_Break", property_value } => { + sb(property_value) + } + ByValue { property_name: "Word_Break", property_value } => { + wb(property_value) + } + _ => { + // What else should we support? + Err(Error::PropertyNotFound) + } + } +} + +/// Returns a Unicode aware class for \w. +/// +/// This returns an error if the data is not available for \w. +pub fn perl_word() -> Result<hir::ClassUnicode> { + #[cfg(not(feature = "unicode-perl"))] + fn imp() -> Result<hir::ClassUnicode> { + Err(Error::PerlClassNotFound) + } + + #[cfg(feature = "unicode-perl")] + fn imp() -> Result<hir::ClassUnicode> { + use crate::unicode_tables::perl_word::PERL_WORD; + Ok(hir_class(PERL_WORD)) + } + + imp() +} + +/// Returns a Unicode aware class for \s. +/// +/// This returns an error if the data is not available for \s. +pub fn perl_space() -> Result<hir::ClassUnicode> { + #[cfg(not(any(feature = "unicode-perl", feature = "unicode-bool")))] + fn imp() -> Result<hir::ClassUnicode> { + Err(Error::PerlClassNotFound) + } + + #[cfg(all(feature = "unicode-perl", not(feature = "unicode-bool")))] + fn imp() -> Result<hir::ClassUnicode> { + use crate::unicode_tables::perl_space::WHITE_SPACE; + Ok(hir_class(WHITE_SPACE)) + } + + #[cfg(feature = "unicode-bool")] + fn imp() -> Result<hir::ClassUnicode> { + use crate::unicode_tables::property_bool::WHITE_SPACE; + Ok(hir_class(WHITE_SPACE)) + } + + imp() +} + +/// Returns a Unicode aware class for \d. +/// +/// This returns an error if the data is not available for \d. +pub fn perl_digit() -> Result<hir::ClassUnicode> { + #[cfg(not(any(feature = "unicode-perl", feature = "unicode-gencat")))] + fn imp() -> Result<hir::ClassUnicode> { + Err(Error::PerlClassNotFound) + } + + #[cfg(all(feature = "unicode-perl", not(feature = "unicode-gencat")))] + fn imp() -> Result<hir::ClassUnicode> { + use crate::unicode_tables::perl_decimal::DECIMAL_NUMBER; + Ok(hir_class(DECIMAL_NUMBER)) + } + + #[cfg(feature = "unicode-gencat")] + fn imp() -> Result<hir::ClassUnicode> { + use crate::unicode_tables::general_category::DECIMAL_NUMBER; + Ok(hir_class(DECIMAL_NUMBER)) + } + + imp() +} + +/// Build a Unicode HIR class from a sequence of Unicode scalar value ranges. +pub fn hir_class(ranges: &[(char, char)]) -> hir::ClassUnicode { + let hir_ranges: Vec<hir::ClassUnicodeRange> = ranges + .iter() + .map(|&(s, e)| hir::ClassUnicodeRange::new(s, e)) + .collect(); + hir::ClassUnicode::new(hir_ranges) +} + +/// Returns true only if the given codepoint is in the `\w` character class. +/// +/// If the `unicode-perl` feature is not enabled, then this returns an error. +pub fn is_word_character(c: char) -> result::Result<bool, UnicodeWordError> { + #[cfg(not(feature = "unicode-perl"))] + fn imp(_: char) -> result::Result<bool, UnicodeWordError> { + Err(UnicodeWordError(())) + } + + #[cfg(feature = "unicode-perl")] + fn imp(c: char) -> result::Result<bool, UnicodeWordError> { + use crate::is_word_byte; + use crate::unicode_tables::perl_word::PERL_WORD; + use std::cmp::Ordering; + + if c <= 0x7F as char && is_word_byte(c as u8) { + return Ok(true); + } + Ok(PERL_WORD + .binary_search_by(|&(start, end)| { + if start <= c && c <= end { + Ordering::Equal + } else if start > c { + Ordering::Greater + } else { + Ordering::Less + } + }) + .is_ok()) + } + + imp(c) +} + +/// A mapping of property values for a specific property. +/// +/// The first element of each tuple is a normalized property value while the +/// second element of each tuple is the corresponding canonical property +/// value. +type PropertyValues = &'static [(&'static str, &'static str)]; + +fn canonical_gencat(normalized_value: &str) -> Result<Option<&'static str>> { + Ok(match normalized_value { + "any" => Some("Any"), + "assigned" => Some("Assigned"), + "ascii" => Some("ASCII"), + _ => { + let gencats = property_values("General_Category")?.unwrap(); + canonical_value(gencats, normalized_value) + } + }) +} + +fn canonical_script(normalized_value: &str) -> Result<Option<&'static str>> { + let scripts = property_values("Script")?.unwrap(); + Ok(canonical_value(scripts, normalized_value)) +} + +/// Find the canonical property name for the given normalized property name. +/// +/// If no such property exists, then `None` is returned. +/// +/// The normalized property name must have been normalized according to +/// UAX44 LM3, which can be done using `symbolic_name_normalize`. +/// +/// If the property names data is not available, then an error is returned. +fn canonical_prop(normalized_name: &str) -> Result<Option<&'static str>> { + #[cfg(not(any( + feature = "unicode-age", + feature = "unicode-bool", + feature = "unicode-gencat", + feature = "unicode-perl", + feature = "unicode-script", + feature = "unicode-segment", + )))] + fn imp(_: &str) -> Result<Option<&'static str>> { + Err(Error::PropertyNotFound) + } + + #[cfg(any( + feature = "unicode-age", + feature = "unicode-bool", + feature = "unicode-gencat", + feature = "unicode-perl", + feature = "unicode-script", + feature = "unicode-segment", + ))] + fn imp(name: &str) -> Result<Option<&'static str>> { + use crate::unicode_tables::property_names::PROPERTY_NAMES; + + Ok(PROPERTY_NAMES + .binary_search_by_key(&name, |&(n, _)| n) + .ok() + .map(|i| PROPERTY_NAMES[i].1)) + } + + imp(normalized_name) +} + +/// Find the canonical property value for the given normalized property +/// value. +/// +/// The given property values should correspond to the values for the property +/// under question, which can be found using `property_values`. +/// +/// If no such property value exists, then `None` is returned. +/// +/// The normalized property value must have been normalized according to +/// UAX44 LM3, which can be done using `symbolic_name_normalize`. +fn canonical_value( + vals: PropertyValues, + normalized_value: &str, +) -> Option<&'static str> { + vals.binary_search_by_key(&normalized_value, |&(n, _)| n) + .ok() + .map(|i| vals[i].1) +} + +/// Return the table of property values for the given property name. +/// +/// If the property values data is not available, then an error is returned. +fn property_values( + canonical_property_name: &'static str, +) -> Result<Option<PropertyValues>> { + #[cfg(not(any( + feature = "unicode-age", + feature = "unicode-bool", + feature = "unicode-gencat", + feature = "unicode-perl", + feature = "unicode-script", + feature = "unicode-segment", + )))] + fn imp(_: &'static str) -> Result<Option<PropertyValues>> { + Err(Error::PropertyValueNotFound) + } + + #[cfg(any( + feature = "unicode-age", + feature = "unicode-bool", + feature = "unicode-gencat", + feature = "unicode-perl", + feature = "unicode-script", + feature = "unicode-segment", + ))] + fn imp(name: &'static str) -> Result<Option<PropertyValues>> { + use crate::unicode_tables::property_values::PROPERTY_VALUES; + + Ok(PROPERTY_VALUES + .binary_search_by_key(&name, |&(n, _)| n) + .ok() + .map(|i| PROPERTY_VALUES[i].1)) + } + + imp(canonical_property_name) +} + +// This is only used in some cases, but small enough to just let it be dead +// instead of figuring out (and maintaining) the right set of features. +#[allow(dead_code)] +fn property_set( + name_map: &'static [(&'static str, Range)], + canonical: &'static str, +) -> Option<Range> { + name_map + .binary_search_by_key(&canonical, |x| x.0) + .ok() + .map(|i| name_map[i].1) +} + +/// Returns an iterator over Unicode Age sets. Each item corresponds to a set +/// of codepoints that were added in a particular revision of Unicode. The +/// iterator yields items in chronological order. +/// +/// If the given age value isn't valid or if the data isn't available, then an +/// error is returned instead. +fn ages(canonical_age: &str) -> Result<impl Iterator<Item = Range>> { + #[cfg(not(feature = "unicode-age"))] + fn imp(_: &str) -> Result<impl Iterator<Item = Range>> { + use std::option::IntoIter; + Err::<IntoIter<Range>, _>(Error::PropertyNotFound) + } + + #[cfg(feature = "unicode-age")] + fn imp(canonical_age: &str) -> Result<impl Iterator<Item = Range>> { + use crate::unicode_tables::age; + + const AGES: &[(&str, Range)] = &[ + ("V1_1", age::V1_1), + ("V2_0", age::V2_0), + ("V2_1", age::V2_1), + ("V3_0", age::V3_0), + ("V3_1", age::V3_1), + ("V3_2", age::V3_2), + ("V4_0", age::V4_0), + ("V4_1", age::V4_1), + ("V5_0", age::V5_0), + ("V5_1", age::V5_1), + ("V5_2", age::V5_2), + ("V6_0", age::V6_0), + ("V6_1", age::V6_1), + ("V6_2", age::V6_2), + ("V6_3", age::V6_3), + ("V7_0", age::V7_0), + ("V8_0", age::V8_0), + ("V9_0", age::V9_0), + ("V10_0", age::V10_0), + ("V11_0", age::V11_0), + ("V12_0", age::V12_0), + ("V12_1", age::V12_1), + ("V13_0", age::V13_0), + ("V14_0", age::V14_0), + ("V15_0", age::V15_0), + ]; + assert_eq!(AGES.len(), age::BY_NAME.len(), "ages are out of sync"); + + let pos = AGES.iter().position(|&(age, _)| canonical_age == age); + match pos { + None => Err(Error::PropertyValueNotFound), + Some(i) => Ok(AGES[..=i].iter().map(|&(_, classes)| classes)), + } + } + + imp(canonical_age) +} + +/// Returns the Unicode HIR class corresponding to the given general category. +/// +/// Name canonicalization is assumed to be performed by the caller. +/// +/// If the given general category could not be found, or if the general +/// category data is not available, then an error is returned. +fn gencat(canonical_name: &'static str) -> Result<hir::ClassUnicode> { + #[cfg(not(feature = "unicode-gencat"))] + fn imp(_: &'static str) -> Result<hir::ClassUnicode> { + Err(Error::PropertyNotFound) + } + + #[cfg(feature = "unicode-gencat")] + fn imp(name: &'static str) -> Result<hir::ClassUnicode> { + use crate::unicode_tables::general_category::BY_NAME; + match name { + "ASCII" => Ok(hir_class(&[('\0', '\x7F')])), + "Any" => Ok(hir_class(&[('\0', '\u{10FFFF}')])), + "Assigned" => { + let mut cls = gencat("Unassigned")?; + cls.negate(); + Ok(cls) + } + name => property_set(BY_NAME, name) + .map(hir_class) + .ok_or(Error::PropertyValueNotFound), + } + } + + match canonical_name { + "Decimal_Number" => perl_digit(), + name => imp(name), + } +} + +/// Returns the Unicode HIR class corresponding to the given script. +/// +/// Name canonicalization is assumed to be performed by the caller. +/// +/// If the given script could not be found, or if the script data is not +/// available, then an error is returned. +fn script(canonical_name: &'static str) -> Result<hir::ClassUnicode> { + #[cfg(not(feature = "unicode-script"))] + fn imp(_: &'static str) -> Result<hir::ClassUnicode> { + Err(Error::PropertyNotFound) + } + + #[cfg(feature = "unicode-script")] + fn imp(name: &'static str) -> Result<hir::ClassUnicode> { + use crate::unicode_tables::script::BY_NAME; + property_set(BY_NAME, name) + .map(hir_class) + .ok_or(Error::PropertyValueNotFound) + } + + imp(canonical_name) +} + +/// Returns the Unicode HIR class corresponding to the given script extension. +/// +/// Name canonicalization is assumed to be performed by the caller. +/// +/// If the given script extension could not be found, or if the script data is +/// not available, then an error is returned. +fn script_extension( + canonical_name: &'static str, +) -> Result<hir::ClassUnicode> { + #[cfg(not(feature = "unicode-script"))] + fn imp(_: &'static str) -> Result<hir::ClassUnicode> { + Err(Error::PropertyNotFound) + } + + #[cfg(feature = "unicode-script")] + fn imp(name: &'static str) -> Result<hir::ClassUnicode> { + use crate::unicode_tables::script_extension::BY_NAME; + property_set(BY_NAME, name) + .map(hir_class) + .ok_or(Error::PropertyValueNotFound) + } + + imp(canonical_name) +} + +/// Returns the Unicode HIR class corresponding to the given Unicode boolean +/// property. +/// +/// Name canonicalization is assumed to be performed by the caller. +/// +/// If the given boolean property could not be found, or if the boolean +/// property data is not available, then an error is returned. +fn bool_property(canonical_name: &'static str) -> Result<hir::ClassUnicode> { + #[cfg(not(feature = "unicode-bool"))] + fn imp(_: &'static str) -> Result<hir::ClassUnicode> { + Err(Error::PropertyNotFound) + } + + #[cfg(feature = "unicode-bool")] + fn imp(name: &'static str) -> Result<hir::ClassUnicode> { + use crate::unicode_tables::property_bool::BY_NAME; + property_set(BY_NAME, name) + .map(hir_class) + .ok_or(Error::PropertyNotFound) + } + + match canonical_name { + "Decimal_Number" => perl_digit(), + "White_Space" => perl_space(), + name => imp(name), + } +} + +/// Returns the Unicode HIR class corresponding to the given grapheme cluster +/// break property. +/// +/// Name canonicalization is assumed to be performed by the caller. +/// +/// If the given property could not be found, or if the corresponding data is +/// not available, then an error is returned. +fn gcb(canonical_name: &'static str) -> Result<hir::ClassUnicode> { + #[cfg(not(feature = "unicode-segment"))] + fn imp(_: &'static str) -> Result<hir::ClassUnicode> { + Err(Error::PropertyNotFound) + } + + #[cfg(feature = "unicode-segment")] + fn imp(name: &'static str) -> Result<hir::ClassUnicode> { + use crate::unicode_tables::grapheme_cluster_break::BY_NAME; + property_set(BY_NAME, name) + .map(hir_class) + .ok_or(Error::PropertyValueNotFound) + } + + imp(canonical_name) +} + +/// Returns the Unicode HIR class corresponding to the given word break +/// property. +/// +/// Name canonicalization is assumed to be performed by the caller. +/// +/// If the given property could not be found, or if the corresponding data is +/// not available, then an error is returned. +fn wb(canonical_name: &'static str) -> Result<hir::ClassUnicode> { + #[cfg(not(feature = "unicode-segment"))] + fn imp(_: &'static str) -> Result<hir::ClassUnicode> { + Err(Error::PropertyNotFound) + } + + #[cfg(feature = "unicode-segment")] + fn imp(name: &'static str) -> Result<hir::ClassUnicode> { + use crate::unicode_tables::word_break::BY_NAME; + property_set(BY_NAME, name) + .map(hir_class) + .ok_or(Error::PropertyValueNotFound) + } + + imp(canonical_name) +} + +/// Returns the Unicode HIR class corresponding to the given sentence +/// break property. +/// +/// Name canonicalization is assumed to be performed by the caller. +/// +/// If the given property could not be found, or if the corresponding data is +/// not available, then an error is returned. +fn sb(canonical_name: &'static str) -> Result<hir::ClassUnicode> { + #[cfg(not(feature = "unicode-segment"))] + fn imp(_: &'static str) -> Result<hir::ClassUnicode> { + Err(Error::PropertyNotFound) + } + + #[cfg(feature = "unicode-segment")] + fn imp(name: &'static str) -> Result<hir::ClassUnicode> { + use crate::unicode_tables::sentence_break::BY_NAME; + property_set(BY_NAME, name) + .map(hir_class) + .ok_or(Error::PropertyValueNotFound) + } + + imp(canonical_name) +} + +/// Like symbolic_name_normalize_bytes, but operates on a string. +fn symbolic_name_normalize(x: &str) -> String { + let mut tmp = x.as_bytes().to_vec(); + let len = symbolic_name_normalize_bytes(&mut tmp).len(); + tmp.truncate(len); + // This should always succeed because `symbolic_name_normalize_bytes` + // guarantees that `&tmp[..len]` is always valid UTF-8. + // + // N.B. We could avoid the additional UTF-8 check here, but it's unlikely + // to be worth skipping the additional safety check. A benchmark must + // justify it first. + String::from_utf8(tmp).unwrap() +} + +/// Normalize the given symbolic name in place according to UAX44-LM3. +/// +/// A "symbolic name" typically corresponds to property names and property +/// value aliases. Note, though, that it should not be applied to property +/// string values. +/// +/// The slice returned is guaranteed to be valid UTF-8 for all possible values +/// of `slice`. +/// +/// See: https://unicode.org/reports/tr44/#UAX44-LM3 +fn symbolic_name_normalize_bytes(slice: &mut [u8]) -> &mut [u8] { + // I couldn't find a place in the standard that specified that property + // names/aliases had a particular structure (unlike character names), but + // we assume that it's ASCII only and drop anything that isn't ASCII. + let mut start = 0; + let mut starts_with_is = false; + if slice.len() >= 2 { + // Ignore any "is" prefix. + starts_with_is = slice[0..2] == b"is"[..] + || slice[0..2] == b"IS"[..] + || slice[0..2] == b"iS"[..] + || slice[0..2] == b"Is"[..]; + if starts_with_is { + start = 2; + } + } + let mut next_write = 0; + for i in start..slice.len() { + // VALIDITY ARGUMENT: To guarantee that the resulting slice is valid + // UTF-8, we ensure that the slice contains only ASCII bytes. In + // particular, we drop every non-ASCII byte from the normalized string. + let b = slice[i]; + if b == b' ' || b == b'_' || b == b'-' { + continue; + } else if b'A' <= b && b <= b'Z' { + slice[next_write] = b + (b'a' - b'A'); + next_write += 1; + } else if b <= 0x7F { + slice[next_write] = b; + next_write += 1; + } + } + // Special case: ISO_Comment has a 'isc' abbreviation. Since we generally + // ignore 'is' prefixes, the 'isc' abbreviation gets caught in the cross + // fire and ends up creating an alias for 'c' to 'ISO_Comment', but it + // is actually an alias for the 'Other' general category. + if starts_with_is && next_write == 1 && slice[0] == b'c' { + slice[0] = b'i'; + slice[1] = b's'; + slice[2] = b'c'; + next_write = 3; + } + &mut slice[..next_write] +} + +#[cfg(test)] +mod tests { + use super::{ + contains_simple_case_mapping, simple_fold, symbolic_name_normalize, + symbolic_name_normalize_bytes, + }; + + #[cfg(feature = "unicode-case")] + fn simple_fold_ok(c: char) -> impl Iterator<Item = char> { + simple_fold(c).unwrap().unwrap() + } + + #[cfg(feature = "unicode-case")] + fn simple_fold_err(c: char) -> Option<char> { + match simple_fold(c).unwrap() { + Ok(_) => unreachable!("simple_fold returned Ok iterator"), + Err(next) => next, + } + } + + #[cfg(feature = "unicode-case")] + fn contains_case_map(start: char, end: char) -> bool { + contains_simple_case_mapping(start, end).unwrap() + } + + #[test] + #[cfg(feature = "unicode-case")] + fn simple_fold_k() { + let xs: Vec<char> = simple_fold_ok('k').collect(); + assert_eq!(xs, vec!['K', 'K']); + + let xs: Vec<char> = simple_fold_ok('K').collect(); + assert_eq!(xs, vec!['k', 'K']); + + let xs: Vec<char> = simple_fold_ok('K').collect(); + assert_eq!(xs, vec!['K', 'k']); + } + + #[test] + #[cfg(feature = "unicode-case")] + fn simple_fold_a() { + let xs: Vec<char> = simple_fold_ok('a').collect(); + assert_eq!(xs, vec!['A']); + + let xs: Vec<char> = simple_fold_ok('A').collect(); + assert_eq!(xs, vec!['a']); + } + + #[test] + #[cfg(feature = "unicode-case")] + fn simple_fold_empty() { + assert_eq!(Some('A'), simple_fold_err('?')); + assert_eq!(Some('A'), simple_fold_err('@')); + assert_eq!(Some('a'), simple_fold_err('[')); + assert_eq!(Some('Ⰰ'), simple_fold_err('☃')); + } + + #[test] + #[cfg(feature = "unicode-case")] + fn simple_fold_max() { + assert_eq!(None, simple_fold_err('\u{10FFFE}')); + assert_eq!(None, simple_fold_err('\u{10FFFF}')); + } + + #[test] + #[cfg(not(feature = "unicode-case"))] + fn simple_fold_disabled() { + assert!(simple_fold('a').is_err()); + } + + #[test] + #[cfg(feature = "unicode-case")] + fn range_contains() { + assert!(contains_case_map('A', 'A')); + assert!(contains_case_map('Z', 'Z')); + assert!(contains_case_map('A', 'Z')); + assert!(contains_case_map('@', 'A')); + assert!(contains_case_map('Z', '[')); + assert!(contains_case_map('☃', 'Ⰰ')); + + assert!(!contains_case_map('[', '[')); + assert!(!contains_case_map('[', '`')); + + assert!(!contains_case_map('☃', '☃')); + } + + #[test] + #[cfg(not(feature = "unicode-case"))] + fn range_contains_disabled() { + assert!(contains_simple_case_mapping('a', 'a').is_err()); + } + + #[test] + #[cfg(feature = "unicode-gencat")] + fn regression_466() { + use super::{CanonicalClassQuery, ClassQuery}; + + let q = ClassQuery::OneLetter('C'); + assert_eq!( + q.canonicalize().unwrap(), + CanonicalClassQuery::GeneralCategory("Other") + ); + } + + #[test] + fn sym_normalize() { + let sym_norm = symbolic_name_normalize; + + assert_eq!(sym_norm("Line_Break"), "linebreak"); + assert_eq!(sym_norm("Line-break"), "linebreak"); + assert_eq!(sym_norm("linebreak"), "linebreak"); + assert_eq!(sym_norm("BA"), "ba"); + assert_eq!(sym_norm("ba"), "ba"); + assert_eq!(sym_norm("Greek"), "greek"); + assert_eq!(sym_norm("isGreek"), "greek"); + assert_eq!(sym_norm("IS_Greek"), "greek"); + assert_eq!(sym_norm("isc"), "isc"); + assert_eq!(sym_norm("is c"), "isc"); + assert_eq!(sym_norm("is_c"), "isc"); + } + + #[test] + fn valid_utf8_symbolic() { + let mut x = b"abc\xFFxyz".to_vec(); + let y = symbolic_name_normalize_bytes(&mut x); + assert_eq!(y, b"abcxyz"); + } +} |