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Add Abjad letters #169

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seloumi wants to merge 3 commits into from
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Add Abjad letters #169

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ac8ccca
Update numeral_systems.rs
seloumi May 27, 2026
5a3cce7
Update numeral_systems.rs
seloumi May 27, 2026
3c208c5
Update numeral_systems.rs
seloumi May 27, 2026
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33 changes: 33 additions & 0 deletions src/numeral_systems.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -408,6 +408,33 @@ declare_named! {
/// > <span dir="auto">٨</span>, <span dir="auto">٩</span>,
/// > <span dir="auto">١٠</span>, <span dir="auto">١١</span>
EasternArabic = "arabic.eastern" ("١"),

/// Abjad order
/// [Arabic letters](https://en.wikipedia.org/wiki/Abjad).
///
/// ## Representable Numbers
///
/// All non-negative integers can be represented.
///
/// ## Example
///
/// The first twenty-eight positive integers are represented as follows:
///
/// > <span dir="auto">أ</span>, <span dir="auto">ب</span>,
/// > <span dir="auto">ج</span>, <span dir="auto">د</span>,
/// > <span dir="auto">ه</span>, <span dir="auto">و</span>,
/// > <span dir="auto">ز</span>, <span dir="auto">ح</span>,
/// > <span dir="auto">ط</span>, <span dir="auto">ي</span>,
/// > <span dir="auto">ك</span>, <span dir="auto">ل</span>
/// > <span dir="auto">م</span>, <span dir="auto">ن</span>
/// > <span dir="auto">س</span>, <span dir="auto">ع</span>
/// > <span dir="auto">ف</span>, <span dir="auto">ص</span>
/// > <span dir="auto">ق</span>, <span dir="auto">ر</span>
/// > <span dir="auto">ش</span>, <span dir="auto">ت</span>
/// > <span dir="auto">ث</span>, <span dir="auto">خ</span>
/// > <span dir="auto">ذ</span>, <span dir="auto">ض</span>
/// > <span dir="auto">ظ</span>, <span dir="auto">غ</span>
ArabicAbjad = "arabic.abjad" ("أ"),

/// Decimal positional notation using the Persian variant of
/// [Eastern Arabic numerals](https://en.wikipedia.org/wiki/Eastern_Arabic_numerals#Numerals).
Expand Down Expand Up @@ -821,6 +848,11 @@ impl NamedNumeralSystem {
Self::EasternArabic => NumeralSystem::Positional(&[
'٠', '١', '٢', '٣', '٤', '٥', '٦', '٧', '٨', '٩',
]),

Self::ArabicAbjad => NumeralSystem::Positional(&[
'أ', 'ب', 'ج', 'د', 'ه', 'و', 'ز', 'ح', 'ط', 'ي', 'ك', 'ل', 'م', 'ن',
'س', 'ع', 'ف', 'ص', 'ق', 'ر', 'ش', 'ت', 'ث', 'خ', 'ذ', 'ض', 'ظ', 'غ',
]),
Comment on lines +852 to +855
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@MDLC01 MDLC01 May 27, 2026

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If I understand properly, this is a system where the first letter has value one, then all the way up to the last letter of the alphabet, and then you start using multiple letters? If this is the case, you should use Bijective instead of Positional. Otherwise, could you please elaborate on how this numeral system works?

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@seloumi seloumi May 27, 2026

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Users will mostly not need all this numbering; the first ten are sufficient.

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@MDLC01 MDLC01 May 27, 2026

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The most important reason why we want to use Bijective is that the first letter should have the value one instead of zero. For example, when using numbered headings in Typst, if using Positional, the first letter would always be skipped because the first heading has the number one.


Self::Persian => NumeralSystem::Positional(&[
'۰', '۱', '۲', '۳', '۴', '۵', '۶', '۷', '۸', '۹',
Expand Down Expand Up @@ -1435,6 +1467,7 @@ mod tests {
NamedNumeralSystem::KoreanJamo => 65477685939649764827530478995838083425, // 21
NamedNumeralSystem::KoreanSyllable => 24217153056183571894327643661698510954,
NamedNumeralSystem::EasternArabic => 277754701051910363703826860323053920831,
NamedNumeralSystem::ArabicAbjad => 332217778941065507236060222268877272547,
NamedNumeralSystem::Persian => 6232158096065129450489636457808686806,
NamedNumeralSystem::Devanagari => 327133969362282954753636774557232534052,
NamedNumeralSystem::Tibetan => 87580519645280744681237273097105390953,
Expand Down
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