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jacegu/roman_numerals.erl

Created April 15, 2013 14:39
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  1. jacegu created this gist Apr 15, 2013.
    36 changes: 36 additions & 0 deletions roman_numerals.erl
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    -module(kata).
    -include_lib("eunit/include/eunit.hrl").

    to_roman(Arabic) when Arabic >= 50 -> string:concat("L", to_roman(Arabic - 50));
    to_roman(Arabic) when Arabic >= 10 -> string:concat("X", to_roman(Arabic - 10));
    to_roman(Arabic) when Arabic >= 5 -> string:concat("V", to_roman(Arabic - 5));
    to_roman(Arabic) when Arabic =:= 4 -> string:concat("IV", to_roman(Arabic - 4));
    to_roman(Arabic) when Arabic >= 1 -> string:concat("I", to_roman(Arabic - 1));
    to_roman(_) -> "".

    it_transform_the_number_1_to_roman_numeral_I_test() ->
    ?assertEqual("I", to_roman(1)).

    it_transform_the_number_2_to_roman_numeral_II_test() ->
    ?assertEqual("II", to_roman(2)).

    it_transform_the_number_3_to_roman_numeral_III_test() ->
    ?assertEqual("III", to_roman(3)).

    it_transform_the_number_4_to_roman_numeral_IV_test() ->
    ?assertEqual("IV", to_roman(4)).

    it_transform_the_number_5_to_roman_numeral_V_test() ->
    ?assertEqual("V", to_roman(5)).

    it_transform_the_number_7_to_roman_numeral_VII_test() ->
    ?assertEqual("VII", to_roman(7)).

    it_transforms_the_number_10_to_roman_numeral_X_test() ->
    ?assertEqual("X", to_roman(10)).

    it_transforms_the_number_37_to_roman_numeral_XXXVII_test() ->
    ?assertEqual("XXXVII", to_roman(37)).

    it_transforms_the_number_57_to_roman_numeral_LVII_test() ->
    ?assertEqual("LVII", to_roman(57)).