"double symbol"

[denis]

Hi! Maybe a simple question, but why double symbol is not detected as symbol?

Code: Select all

(symbol? ''a) ; -> nil
; but
(symbol? (eval ''a)) ; -> true

What type of object is ''a (or e.g. '''''''''''''''''''''a) then?

[cormullion]

Probably a quoted expression.

Code: Select all

> (quote? ''a)
true
> (quote? 'a)
nil

Don't know for sure, though.

[denis]

Oh, true. Thanks, cormullion!
Needed this to analyze what macroses get in the (args). Complex cases happen when macro calls another macro. Maybe I go in wrong way, but for the moment current the question how to detect the form (type) of argument is relevant :-)