# Nominals
[](https://crates.io/crates/nominals)
[](https://docs.rs/nominals)
This type of formatting can be used for list identifiers when creating ordered
lists similar to HTML's `<ol>` tag. The crate was written to power the
`List` widget in [Cushy][cushy].
This crate's original implementation was inspired by [Typst][typst]'s
implementation of list numbering. However, this crate is a fresh implementation
with newly-written implementations and types.
```rust
use nominals::{Decimal, DigitCollection, Error, LetterLower, Nominal};
fn main() {
// Formatting a nominal is as easy as calling to_nominal with the desired
// nominal system.
assert_eq!(0_u32.to_nominal(&Decimal), "0");
// By default, alphabet systems treat their first symbol as 0 in the ones
// place, but treat the first symbol as 1 in every other digit place.
assert_eq!(0_u32.to_nominal(&LetterLower), "a");
assert_eq!(1_u32.to_nominal(&LetterLower), "b");
assert_eq!(26_u32.to_nominal(&LetterLower), "aa");
// This behavior can be changed by using the one_based helper:
assert_eq!(1_u32.to_nominal(&LetterLower.one_based()), "a");
assert_eq!(2_u32.to_nominal(&LetterLower.one_based()), "b");
assert_eq!(27_u32.to_nominal(&LetterLower.one_based()), "aa");
// When a nominal can't be formatted with `to_nominal`, it falls back to
// Decimal.
assert_eq!(0_u32.to_nominal(&LetterLower.one_based()), "0");
assert_eq!(
0_u32.try_to_nominal(&LetterLower.one_based()).unwrap_err(),
Error::NoZeroSymbol
);
}
```
## `no_std` support
This crate is `no_std` compatible, and can operate both with and without
`alloc`.
[cushy]: https://github.com/khonsulabs/cushy
[typst]: https://github.com/typst/typst
## Supported Systems
- [`Decimal`](https://docs.rs/nominals/latest/nominals/struct.Decimal.html): 0 1 2 3 4 … 9 10 11 12 … 99 100 101 102
- [`LetterLower`](https://docs.rs/nominals/latest/nominals/struct.LetterLower.html): a b c d e … z aa ab ac … yz za zb zc
- [`LetterUpper`](https://docs.rs/nominals/latest/nominals/struct.LetterUpper.html): A B C D E … Z AA AB AC … YZ ZA ZB ZC
- [`RomanLower`](https://docs.rs/nominals/latest/nominals/struct.RomanLower.html): i ii iii iv v vi … ix x xi … mmmcmxcix i̅v̅ i̅v̅i … d̅m̅l̅c̅i̅x̅cmxcix m̅ m̅i
- [`RomanUpper`](https://docs.rs/nominals/latest/nominals/struct.RomanUpper.html): I II III IV V VI … IX X XI … MMMCMXCIX I̅V̅ I̅V̅I … D̅M̅L̅C̅I̅X̅CMXCIX M̅ M̅I
- [`ArmenianLower`](https://docs.rs/nominals/latest/nominals/struct.ArmenianLower.html): ա բ գ … թ ժ ժա ժբ … ղթ ճ ճա
- [`ArmenianUpper`](https://docs.rs/nominals/latest/nominals/struct.ArmenianUpper.html): Ա Բ Գ … Թ Ժ ԺԱ ԺԲ … ՂԹ Ճ ՃԱ
- [`Bengali`](https://docs.rs/nominals/latest/nominals/struct.Bengali.html): ০ ১ ২ ৩ ৪ … ৯ ১০ ১১ ১২ … ৯৯ ১০০ ১০১ ১০২
- [`Cambodian`](https://docs.rs/nominals/latest/nominals/struct.Cambodian.html): ០ ១ ២ ៣ ៤ … ៩ ១០ ១១ ១២ … ៩៩ ១០០ ១០១ ១០២
- [`SimplifiedChineseInformal`](https://docs.rs/nominals/latest/nominals/struct.SimplifiedChineseInformal.html): 零 一 二 … 九 十 十一 … 十九 二十 二十一 … 九十九 一百 一百零一
- [`TraditionalChineseInformal`](https://docs.rs/nominals/latest/nominals/struct.TraditionalChineseInformal.html): 零 一 二 … 九 十 十一 … 十九 二十 二十一 … 九十九 一百 一百零一
- [`SimplifiedChineseFormal`](https://docs.rs/nominals/latest/nominals/struct.SimplifiedChineseFormal.html): 零 一 二 … 九 一十 一十一 … 一十九 二十 二十一 … 九十九 一百 一百零一
- [`TraditionalChineseFormal`](https://docs.rs/nominals/latest/nominals/struct.TraditionalChineseFormal.html): 零 一 二 … 九 一十 一十一 … 一十九 二十 二十一 … 九十九 一百 一百零一
- [`CjkDecimal`](https://docs.rs/nominals/latest/nominals/struct.CjkDecimal.html): 〇 一 二 三 四 … 九 一〇 一一 一二 … 九九 一〇〇 一〇一 一〇二
- [`CjkEarthlyBranch`](https://docs.rs/nominals/latest/nominals/struct.CjkEarthlyBranch.html): 子 丑 寅 卯 辰 … 亥 一子 一丑 一寅 … 九亥 一〇子 一〇丑 一〇寅
- [`CjkHeavenlyStem`](https://docs.rs/nominals/latest/nominals/struct.CjkHeavenlyStem.html): 甲 乙 丙 丁 戊 … 癸 一甲 一乙 一丙 … 九癸 一〇甲 一〇乙 一〇丙
- [`Devanagari`](https://docs.rs/nominals/latest/nominals/struct.Devanagari.html): ० १ २ ३ ४ … ९ १० ११ १२ … ९९ १०० १०१ १०२
- [`EasternArabic`](https://docs.rs/nominals/latest/nominals/struct.EasternArabic.html): ٠ ١ ٢ ٣ ٤ … ٩ ١٠ ١١ ١٢ … ٩٩ ١٠٠ ١٠١ ١٠٢
- [`Ethiopic`](https://docs.rs/nominals/latest/nominals/struct.Ethiopic.html): ፩ ፪ ፫ … ፲ ፲፩ ፲፪ … ፺፱ ፻ ፻፩ … ፱፻፺፱ ፲፻ ፲፻፩
- [`Georgian`](https://docs.rs/nominals/latest/nominals/struct.Georgian.html): ა ბ გ … თ ი ია იბ … ჟთ რ რა
- [`GreekLower`](https://docs.rs/nominals/latest/nominals/struct.GreekLower.html): α β γ δ ε … ω αα αβ αγ … ψω ωα ωβ ωγ
- [`GreekUpper`](https://docs.rs/nominals/latest/nominals/struct.GreekUpper.html): Α Β Γ Δ Ε … Ω ΑΑ ΑΒ ΑΓ … ΨΩ ΩΑ ΩΒ ΩΓ
- [`Gujarati`](https://docs.rs/nominals/latest/nominals/struct.Gujarati.html): ૦ ૧ ૨ ૩ ૪ … ૯ ૧૦ ૧૧ ૧૨ … ૯૯ ૧૦૦ ૧૦૧ ૧૦૨
- [`Gurmukhi`](https://docs.rs/nominals/latest/nominals/struct.Gurmukhi.html): ੦ ੧ ੨ ੩ ੪ … ੯ ੧੦ ੧੧ ੧੨ … ੯੯ ੧੦੦ ੧੦੧ ੧੦੨
- [`HangeulFormal`](https://docs.rs/nominals/latest/nominals/struct.HangeulFormal.html): 영 일 이 … 구 일십 일십일 … 일십구 이십 이십일 … 구십구 일백 일백일
- [`HangeulInformal`](https://docs.rs/nominals/latest/nominals/struct.HangeulInformal.html): 零 一 二 … 九 十 十一 … 十九 二十 二十一 … 九十九 百 百一
- [`HangeulJamo`](https://docs.rs/nominals/latest/nominals/struct.HangeulJamo.html): ㄱ ㄴ ㄷ ㄹ ㅁ … ㅎ ㄱㄱ ㄱㄴ ㄱㄷ … ㅍㅎ ㅎㄱ ㅎㄴ ㅎㄷ
- [`HangeulSyllable`](https://docs.rs/nominals/latest/nominals/struct.HangeulSyllable.html): 가 나 다 라 마 … 하 가가 가나 가다 … 파하 하가 하나 하다
- [`HanjaFormal`](https://docs.rs/nominals/latest/nominals/struct.HanjaFormal.html): 零 壹 貳 … 九 壹拾 壹拾壹 … 壹拾九 貳拾 貳拾壹 … 九拾九 壹百 壹百壹
- [`Hebrew`](https://docs.rs/nominals/latest/nominals/struct.Hebrew.html): ׳א״ ׳ב״ ׳ג״ … ׳ט״ ׳י״ … יג יד ט״ו ט״ז יז … שצו שצז שצח שצט ׳ת״
- [`HexLower`](https://docs.rs/nominals/latest/nominals/struct.HexLower.html): 0 1 2 3 4 … f 10 11 12 … ff 100 101 102
- [`HexUpper`](https://docs.rs/nominals/latest/nominals/struct.HexUpper.html): 0 1 2 3 4 … F 10 11 12 … FF 100 101 102
- [`Hiragana`](https://docs.rs/nominals/latest/nominals/struct.Hiragana.html): あ い う え お … ん ああ あい あう … をん んあ んい んう
- [`HiraganaIroha`](https://docs.rs/nominals/latest/nominals/struct.HiraganaIroha.html): い ろ は に ほ … す いい いろ いは … せす すい すろ すは
- [`JapaneseFormal`](https://docs.rs/nominals/latest/nominals/struct.JapaneseFormal.html): 零 壱 弐 … 九 壱拾 壱拾壱 … 壱拾九 弐拾 弐拾壱 … 九拾九 壱百 壱百壱
- [`JapaneseInformal`](https://docs.rs/nominals/latest/nominals/struct.JapaneseInformal.html): 〇 一 二 … 九 十 十一 … 十九 二十 二十一 … 九十九 百 百一
- [`Kannada`](https://docs.rs/nominals/latest/nominals/struct.Kannada.html): ೦ ೧ ೨ ೩ ೪ … ೯ ೧೦ ೧೧ ೧೨ … ೯೯ ೧೦೦ ೧೦೧ ೧೦೨
- [`Katakana`](https://docs.rs/nominals/latest/nominals/struct.Katakana.html): ア イ ウ エ オ … ン アア アイ アウ … ヲン ンア ンイ ンウ
- [`KatakanaIroha`](https://docs.rs/nominals/latest/nominals/struct.KatakanaIroha.html): イ ロ ハ ニ ホ … ス イイ イロ イハ … セス スイ スロ スハ
- [`Lao`](https://docs.rs/nominals/latest/nominals/struct.Lao.html): ໐ ໑ ໒ ໓ ໔ … ໙ ໑໐ ໑໑ ໑໒ … ໙໙ ໑໐໐ ໑໐໑ ໑໐໒
- [`Malayalam`](https://docs.rs/nominals/latest/nominals/struct.Malayalam.html): ൦ ൧ ൨ ൩ ൪ … ൯ ൧൦ ൧൧ ൧൨ … ൯൯ ൧൦൦ ൧൦൧ ൧൦൨
- [`Mongolian`](https://docs.rs/nominals/latest/nominals/struct.Mongolian.html): ᠐ ᠑ ᠒ ᠓ ᠔ … ᠙ ᠑᠐ ᠑᠑ ᠑᠒ … ᠙᠙ ᠑᠐᠐ ᠑᠐᠑ ᠑᠐᠒
- [`Myanmar`](https://docs.rs/nominals/latest/nominals/struct.Myanmar.html): ၀ ၁ ၂ ၃ ၄ … ၉ ၁၀ ၁၁ ၁၂ … ၉၉ ၁၀၀ ၁၀၁ ၁၀၂
- [`Oriya`](https://docs.rs/nominals/latest/nominals/struct.Oriya.html): ୦ ୧ ୨ ୩ ୪ … ୯ ୧୦ ୧୧ ୧୨ … ୯୯ ୧୦୦ ୧୦୧ ୧୦୨
- [`Persian`](https://docs.rs/nominals/latest/nominals/struct.Persian.html): ۰ ۱ ۲ ۳ ۴ … ۹ ۱۰ ۱۱ ۱۲ … ۹۹ ۱۰۰ ۱۰۱ ۱۰۲
- [`Tamil`](https://docs.rs/nominals/latest/nominals/struct.Tamil.html): ௦ ௧ ௨ ௩ ௪ … ௯ ௧௦ ௧௧ ௧௨ … ௯௯ ௧௦௦ ௧௦௧ ௧௦௨
- [`Telugu`](https://docs.rs/nominals/latest/nominals/struct.Telugu.html): ౦ ౧ ౨ ౩ ౪ … ౯ ౧౦ ౧౧ ౧౨ … ౯౯ ౧౦౦ ౧౦౧ ౧౦౨
- [`Thai`](https://docs.rs/nominals/latest/nominals/struct.Thai.html): ๐ ๑ ๒ ๓ ๔ … ๙ ๑๐ ๑๑ ๑๒ … ๙๙ ๑๐๐ ๑๐๑ ๑๐๒
- [`Tibetan`](https://docs.rs/nominals/latest/nominals/struct.Tibetan.html): ༠ ༡ ༢ ༣ ༤ … ༩ ༡༠ ༡༡ ༡༢ … ༩༩ ༡༠༠ ༡༠༡ ༡༠༢
## Open-source Licenses
This project, like all projects from [Khonsu Labs](https://khonsulabs.com/), is open-source.
This repository is available under the [MIT License](./LICENSE-MIT) or the
[Apache License 2.0](./LICENSE-APACHE).
To learn more about contributing, please see [CONTRIBUTING.md](./CONTRIBUTING.md).