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Read decimal digit values from the bundled character database #8748

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Merged
youknowone merged 1 commit into from
Sep 20, 2026
Merged

Read decimal digit values from the bundled character database #8748

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60 changes: 20 additions & 40 deletions crates/common/src/str.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -797,48 +797,15 @@ macro_rules! ascii {
}
pub use ascii;

// TODO: this should probably live in a crate like unic or unicode-properties
const UNICODE_DECIMAL_VALUES: &[char] = &[
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '٠', '١', '٢', '٣', '٤', '٥', '٦', '٧', '٨',
'٩', '۰', '۱', '۲', '۳', '۴', '۵', '۶', '۷', '۸', '۹', '߀', '߁', '߂', '߃', '߄', '߅', '߆', '߇',
'߈', '߉', '०', '१', '२', '३', '४', '५', '६', '७', '८', '९', '০', '১', '২', '৩', '৪', '৫', '৬',
'৭', '৮', '৯', '੦', '੧', '੨', '੩', '੪', '੫', '੬', '੭', '੮', '੯', '૦', '૧', '૨', '૩', '૪', '૫',
'૬', '૭', '૮', '૯', '୦', '୧', '୨', '୩', '୪', '୫', '୬', '୭', '୮', '୯', '௦', '௧', '௨', '௩', '௪',
'௫', '௬', '௭', '௮', '௯', '౦', '౧', '౨', '౩', '౪', '౫', '౬', '౭', '౮', '౯', '೦', '೧', '೨', '೩',
'೪', '೫', '೬', '೭', '೮', '೯', '൦', '൧', '൨', '൩', '൪', '൫', '൬', '൭', '൮', '൯', '෦', '෧', '෨',
'෩', '෪', '෫', '෬', '෭', '෮', '෯', '๐', '๑', '๒', '๓', '๔', '๕', '๖', '๗', '๘', '๙', '໐', '໑',
'໒', '໓', '໔', '໕', '໖', '໗', '໘', '໙', '༠', '༡', '༢', '༣', '༤', '༥', '༦', '༧', '༨', '༩', '၀',
'၁', '၂', '၃', '၄', '၅', '၆', '၇', '၈', '၉', '႐', '႑', '႒', '႓', '႔', '႕', '႖', '႗', '႘', '႙',
'០', '១', '២', '៣', '៤', '៥', '៦', '៧', '៨', '៩', '᠐', '᠑', '᠒', '᠓', '᠔', '᠕', '᠖', '᠗', '᠘',
'᠙', '᥆', '᥇', '᥈', '᥉', '᥊', '᥋', '᥌', '᥍', '᥎', '᥏', '᧐', '᧑', '᧒', '᧓', '᧔', '᧕', '᧖', '᧗',
'᧘', '᧙', '᪀', '᪁', '᪂', '᪃', '᪄', '᪅', '᪆', '᪇', '᪈', '᪉', '᪐', '᪑', '᪒', '᪓', '᪔', '᪕', '᪖',
'᪗', '᪘', '᪙', '᭐', '᭑', '᭒', '᭓', '᭔', '᭕', '᭖', '᭗', '᭘', '᭙', '᮰', '᮱', '᮲', '᮳', '᮴', '᮵',
'᮶', '᮷', '᮸', '᮹', '᱀', '᱁', '᱂', '᱃', '᱄', '᱅', '᱆', '᱇', '᱈', '᱉', '᱐', '᱑', '᱒', '᱓', '᱔',
'᱕', '᱖', '᱗', '᱘', '᱙', '꘠', '꘡', '꘢', '꘣', '꘤', '꘥', '꘦', '꘧', '꘨', '꘩', '꣐', '꣑', '꣒', '꣓',
'꣔', '꣕', '꣖', '꣗', '꣘', '꣙', '꤀', '꤁', '꤂', '꤃', '꤄', '꤅', '꤆', '꤇', '꤈', '꤉', '꧐', '꧑', '꧒',
'꧓', '꧔', '꧕', '꧖', '꧗', '꧘', '꧙', '꧰', '꧱', '꧲', '꧳', '꧴', '꧵', '꧶', '꧷', '꧸', '꧹', '꩐', '꩑',
'꩒', '꩓', '꩔', '꩕', '꩖', '꩗', '꩘', '꩙', '꯰', '꯱', '꯲', '꯳', '꯴', '꯵', '꯶', '꯷', '꯸', '꯹', '０',
'１', '２', '３', '４', '５', '６', '７', '８', '９', '𐒠', '𐒡', '𐒢', '𐒣', '𐒤', '𐒥', '𐒦', '𐒧',
'𐒨', '𐒩', '𑁦', '𑁧', '𑁨', '𑁩', '𑁪', '𑁫', '𑁬', '𑁭', '𑁮', '𑁯', '𑃰', '𑃱', '𑃲', '𑃳', '𑃴', '𑃵', '𑃶',
'𑃷', '𑃸', '𑃹', '𑄶', '𑄷', '𑄸', '𑄹', '𑄺', '𑄻', '𑄼', '𑄽', '𑄾', '𑄿', '𑇐', '𑇑', '𑇒', '𑇓', '𑇔', '𑇕',
'𑇖', '𑇗', '𑇘', '𑇙', '𑋰', '𑋱', '𑋲', '𑋳', '𑋴', '𑋵', '𑋶', '𑋷', '𑋸', '𑋹', '𑑐', '𑑑', '𑑒', '𑑓', '𑑔',
'𑑕', '𑑖', '𑑗', '𑑘', '𑑙', '𑓐', '𑓑', '𑓒', '𑓓', '𑓔', '𑓕', '𑓖', '𑓗', '𑓘', '𑓙', '𑙐', '𑙑', '𑙒', '𑙓',
'𑙔', '𑙕', '𑙖', '𑙗', '𑙘', '𑙙', '𑛀', '𑛁', '𑛂', '𑛃', '𑛄', '𑛅', '𑛆', '𑛇', '𑛈', '𑛉', '𑜰', '𑜱', '𑜲',
'𑜳', '𑜴', '𑜵', '𑜶', '𑜷', '𑜸', '𑜹', '𑣠', '𑣡', '𑣢', '𑣣', '𑣤', '𑣥', '𑣦', '𑣧', '𑣨', '𑣩', '𑱐', '𑱑',
'𑱒', '𑱓', '𑱔', '𑱕', '𑱖', '𑱗', '𑱘', '𑱙', '𑵐', '𑵑', '𑵒', '𑵓', '𑵔', '𑵕', '𑵖', '𑵗', '𑵘', '𑵙', '𖩠',
'𖩡', '𖩢', '𖩣', '𖩤', '𖩥', '𖩦', '𖩧', '𖩨', '𖩩', '𖭐', '𖭑', '𖭒', '𖭓', '𖭔', '𖭕', '𖭖', '𖭗', '𖭘', '𖭙',
'𝟎', '𝟏', '𝟐', '𝟑', '𝟒', '𝟓', '𝟔', '𝟕', '𝟖', '𝟗', '𝟘', '𝟙', '𝟚', '𝟛', '𝟜', '𝟝', '𝟞', '𝟟', '𝟠',
'𝟡', '𝟢', '𝟣', '𝟤', '𝟥', '𝟦', '𝟧', '𝟨', '𝟩', '𝟪', '𝟫', '𝟬', '𝟭', '𝟮', '𝟯', '𝟰', '𝟱', '𝟲', '𝟳',
'𝟴', '𝟵', '𝟶', '𝟷', '𝟸', '𝟹', '𝟺', '𝟻', '𝟼', '𝟽', '𝟾', '𝟿', '𞥐', '𞥑', '𞥒', '𞥓', '𞥔', '𞥕', '𞥖',
'𞥗', '𞥘', '𞥙',
];

/// The decimal digit value of `ch`, if it has one — CPython's `Py_UNICODE_TODECIMAL`.
///
/// Reads the bundled character database, the same source `unicodedata.decimal`
/// consults, so the two can never disagree and new scripts are picked up with the
/// next Unicode update.
#[must_use]
pub fn char_to_decimal(ch: char) -> Option<u8> {
UNICODE_DECIMAL_VALUES
.binary_search(&ch)
.ok()
.map(|i| (i % 10) as u8)
let value = rustpython_unicode::Ucd::new(true).decimal(CodePoint::from(ch))?;
u8::try_from(value).ok()
}

/// Replace Unicode decimal digits with their ASCII equivalents and any Unicode
Expand Down Expand Up @@ -875,6 +842,19 @@ pub fn transform_decimal_and_space_to_ascii(s: &str) -> Cow<'_, str> {
mod tests {
use super::*;

#[test]
fn char_to_decimal_values() {
assert_eq!(char_to_decimal('7'), Some(7));
// Decimal digits from any script, including scripts the previous
// hand-written table predated.
assert_eq!(char_to_decimal('٣'), Some(3)); // U+0663 Arabic-Indic
assert_eq!(char_to_decimal('𐴵'), Some(5)); // U+10D35, Unicode 11
assert_eq!(char_to_decimal('🯵'), Some(5)); // U+1FBF5, Unicode 13
// Numeric but not a decimal digit, so it has no digit value.
assert_eq!(char_to_decimal('½'), None);
assert_eq!(char_to_decimal('가'), None);
}

#[test]
fn transform_decimal_and_space() {
// ASCII input is passed through untouched, without allocating.
Expand Down
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