romanex v0.1.0 Romanex

Encode, Decode, and Validate roman numerals.

Letter values are:

M = 1000, D = 500, C = 100, L = 50, X = 10, V = 5, I = 1

The Range of Values representable by roman numerals is:

1 - 4999

Summary

Functions

decode(rnum)

Decode a Roman Numeral into an Integer

encode(int)

Encode an Integer into a Roman Numeral

valid?(rnum)

Validates a Roman Numeral. Returns true or false

Functions

decode(rnum)

Specs

decode(String.t) :: {:ok | :error, non_neg_integer}

Decode a Roman Numeral into an Integer

Returns {:ok, result} or {:error, position-of-error}

Lesser value letters that come after Higher value letters signify addition. Only 1 letter may be subtracted from another letter.

EX: 8 is VIII and never IIX.

Subtraction can only occur if the result does not equal another letter.

EX: 50 is never LC, as L is alread 50.

Lesser value letters that come before Higher value letters signify subtraction. Letters that are repeated signify addition. A letter may be repeated at most 3 times.

EX: 4 is always IV and never IIII

Addition can only occur if the result does not equal another letter.

EX: 100 is always C and never LL

V, L, and D may appear only once. I, X, C, and M may appear up to 4 times.

encode(int)

Specs

encode(integer) :: {atom, String.t}

Encode an Integer into a Roman Numeral.

valid?(rnum)

Specs

valid?(String.t) :: boolean

Validates a Roman Numeral. Returns true or false