class Library < Array
def add_book(author, title)
self << [author, title]
end
def search_by_author(key)
reject { |b| !match(b, 0, key) }
end
def search_by_author_or_title(key)
reject { |b| !match(b, 0, key) && !match(b, 1, key) }
end
:private
def match(b, index, key)
b[index].index(key) != nil
end
def method_missing(m, *args)
search_by_author_or_title(m.to_s)
end
end
l = Library.new("author","title")
p l.a
p l.b
p l.c