On Mon, 2011-10-17 at 04:32 +0000, Guofeng Zhang wrote:
>     `(let [~@(mapcat (fn [[k v]] [k `'~v]) ctx)]
> 
> And the sample output:
> (contextual-eval {'a 1, 'b 2} '(+ a b))
> 
> I do not understand why "`'~v" has be to used this way. If I used "`~v" 
> instead (that is, remove the quote), it still works. So my question is, why 
> "~v" needs to be first quoted and then syntax-quoted?

It appears to work the same in both of your samples because the numbers,
e.g. 1 and 2, are self-evaluating.

Try (contextual-eval '{a (+), b (1 2)} '(concat a b)) to see the
difference.  (Hint: it should yield (+ 1 2), literally.)

-- 
Stephen Compall
^aCollection allSatisfy: [:each|aCondition]: less is better

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