Problem with passing a vector as a binding to the for macro

Question

I have an arbitrary number of lists which I would like to process using the for macro. I want to create a function that passes a vector as the binding since the number of lists

Answer 1

The key is that for is a macro. At macro-expansion time, testvector is a symbol. It will evaluate to a vector at evaluation time, but it's not a vector from the perspective of the for macro.

user=> (defmacro tst [v] (vector? v))
#'user/tst
user=> (tst testvector)
false
user=> (vector? testvector)
true
user=> (defmacro tst2 [v] `(vector? ~v))
#'user/tst2
user=> (tst2 testvector)
true

If you check the source for the for macro (in core.clj), you'll see that for uses an unquoted vector? call, just like tst in the example above.