README.txt

7つの言語 7つの世界 のセルフスタディで書いたコード。

day01_count.erl

-module(day01_count).
-export([count_words/1]).
-export([count_ten/0]).

count_words(Str) ->
	count_words(Str, 1).
count_words([], Num) ->
	Num;
count_words(Str, Num) ->
	[Head|Tail] = Str,
	case Head of
		32 -> count_words(Tail, Num + 1);
		_ -> count_words(Tail, Num)
	end.

count_ten() ->
	count_ten(1).
count_ten(10) ->
	10;
count_ten(Num) ->
	io:write(Num),
	io:nl(),
	count_ten(Num + 1).

day01_errormsg.erl

-module(day01_errormsg).
-export([get_message/1]).

get_message(success) -> io:put_chars("success"), io:nl();
get_message({error, Message}) -> io:put_chars("error: " ++ Message), io:nl().

day02_comprehension.erl

1> Calc = fun({Item, Quantity, Price}) -> {Item, Quantity * Price} end.
#Fun<erl_eval.6.80247286>
2> Calc({"MacBookAir", 110000, 100}).
{"MacBookAir",11000000}
3> Items = [{"MacBookAir", 110000, 5}, {"iPhone", 50000, 10}, {"iPad", 70000, 3}].
[{"MacBookAir",110000,5},
 {"iPhone",50000,10},
 {"iPad",70000,3}]
4> [Calc(Item) || Item <- Items].
[{"MacBookAir",550000},{"iPhone",500000},{"iPad",210000}]

day02_listutil.erl

-module(day02_listutil).
-export([get_key/2]).

get_key(Items, Key) ->
	Check = fun({K,_}) -> K == Key end,
	[{_, V}] = lists:filter(Check, Items),
	V.