From: Caleb Clausen <vikkous@...>
Date: 2010-08-24T01:47:25+09:00
Subject: Re: Your thoughts on #memo ?

On 8/23/10, Intransition <transfire@gmail.com> wrote:
> The use case for #memo is an alternative to:
>
>   def m
>     @m ||= ....
>   end
>
> But differs in that it avoids the need for an instance variable. I
> tend to use the "@m ||=" idiom a lot, though I wonder about it's
> threading implications, and whether something like #memo would be more
> robust.

Your #memo method is no more re-entrant than the instance variable
example you gave above. If you want it to be re-entrant, you need to
have a mutex.

Also, I seem to recall that methods defined via define_method are
slower than methods defined via def. But I couldn't see a way to
rewrite your code using def instead...