note!

At some point before 1.0, this crate is likely going under a moderate re-write.

Korean Numbers

Converting a few different types to hangeul is supported:

• int
• money (f64)
• bigint
• str
• some math expressions

You can choose between Sino-Korean numbers (based on Korean's adopted Chinese characters, 한자), or Pure Korean numbers.

Example Usage

// Get Pure Korean Hangeul
assert_eq!("서른둘", hangeul_from_int(30, false));
assert_eq!("둘", hangeul_from_string(String::from("2"), false));

// Get Sino-Korean Hangeul
assert_eq!("백이십", hangeul_from_int(120, true));
assert_eq!("만 이천삼백사십오", hangeul_from_string(String::from("12345"), true));

// Get Sino-Korean Hangeul from a BigInt
assert_eq!("천극", hangeul_from_bigint(pow(BigInt::from(10), 51))),

// Get Hangeul from a math expression (Sino-Korean only)
assert_eq!("일 더하기 일", "hangeul_from_expression("1 + 1");

// Get Hangeul from money (an f64 which gets truncated to 2 places) (Sino-Korean only)
assert_eq!("일 점 일", "hangeul_from_money(1.1);

About Korean Numbers

Korean utilizes two number systems. One uses numbers that are purely Korean, the other uses numbers that are derived from borrowed Chinese characters (한자).

A confusing aspect is that number groupings are done in terms of 4 zeroes, not 3.

In English, 100,000 is one hundred thousand: 100 * 1,000. In Korean, it's 십만, or 10 * 10,000.

10 = 십 (in Sino-Korean) 10,000 = 만.

In English, 1,000,000 is one million. In Korean, it's 백만, or 100 * 10,000.

100 = 백. 10,000 = 만.

After 만, the next unique word for a grouping is 억, at 10^8. You can see all of the groupings this program supports below.

Lastly, Korean number words are not spaced except for grouping words like 만, 억, 조, and upwards.

Pure Korean Numbers

Pure Korean numbers are only used for numbers 1 through 99. They mirror our twenty, thirty, etc, in that each tens increase has a unique word to memorize.

In real life, it's uncommon to use pure korean numbers over 50 or so.

To show the tens place, the place word comes before the number.

1 is 하나, 10 is 열, 20 is 스물 (in Pure Korean).

1, 2, 3, 4, and 20 can be conjugated as well. todo: add conjugation rules here

Sino-Korean Numbers

Adding a number before a place word like 십, 백, 천, 만, etc, multiplies it. Adding a number after adds it.

3 is 삼, 10 is 십 (in Sino-Korean).

Sino-Korean number support in this program goes up to 10^51:

Wikipedia lists even higher groupings, but at different exponents...

Math Expressions

The following math expressions are supported. When doing math, Sino-Korean numbers are used.

pub enum KoreanMathOp {
    Add,
    Divide,
    Multiply,
    Subtract,
    Pow,
    Fraction,
    LessThan,
    GreaterThan,
    Equal,
    NotEqual,
    Log
}

Further Reading

0. Korean Numbers
1. Big Korean Numbers
2. Wikipedia - Korean Numerals
3. Korean Numbers Reference

Todo

• add conjugations for pure korean numbers
• Add counter enum and mappings
• Add API fn to get a counter for a kind of term
• Add counter information in README