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Re: unquote?
Mark Beierl <mark@texar.com> writes:
> if I use ,a or (unquote a), or just unquote by itself, I get an unbound
> symbol for unquote. I even tried the kawa/GuiConsole from the latest
> cvs sources, and I get the same thing. Is unquote not bound, or am
> I missing the syntax?
Both - unquote has no specific binding *except* in the context
of a backquote. In that case it "undoes" the quotation performed
by the backquote. For example:
`(+ 2 ,(+ 3 4) 5)
evaluates to:
(+ 2 7 5)
The backquote `(+ ...) is the same a '(+ ...) *except* for the
part inside the unquote.
Trying to evaluate `a or (unquote a) in isolation (i.e. not
inside a backquote) has no meaning and is not defined. Unquote
is recognizted at macro-evaluation time as part of backquote
processing.
--
--Per Bothner
per@bothner.com http://www.bothner.com/per/