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Op 14 februari 2012 06:11 schreef Miles Bader <> het volgende:
Sean Conner <> writes:
>> Given an array, produce a "set". local s={}; for _,v in ipairs(a) do
>> s[v]=true done end return s.
>   I don't see the reason for this.  The only two values that evaluate to
> false are false and nil.

It's actually pretty useful, because it allows a nice syntax for
writing fast table-based predicates.

Isn't it even more useful to use not a bare`true` but something active?
E.g. a function to be called?

Personally I prefer a multiset aka histogram: instead of `s[v]=true`,
   s[v] = (s[v] or 0) + 1