Rubyの予約語
BEGIN
class
ensure
nil
self
when
END
def
false
not
super
while
alias
defined?
for
or
then
予約語yield
and
do
if
redo
true
__LINE__
begin
else
in
rescue
undef
__FILE__
break
elsif
module
retry
unless
__ENCODING__
case
end
next
return
until