Hi,
I would like to create an @invisible macro that takes statements and
appends `nothing` at the end. The motivation is to provide something
similar to invisible() in R, if not in implementation then in
functionality, especially because when I am using Gadfly then printing
the plots opens them in the browser and something this is not what I
want (but this is also a good opportunity for the to learn about macros
in Julia, regardless of the application).
So
@invisible(p1=plot(x=x1, y=y1), p2=plot(x=x2, y=y2))
would expand to
begin
p1=plot(x=x1, y=y1)
p2=plot(x=x2, y=y2)
nothing
end
A Common Lisp implementation would be something like
(defmacro invisible (&body body)
`(progn ,@body nil))
so I tried
macro invisible(expressions...)
quote
$(expressions...)
nothing
end
end
which I thought works fine because
julia> macroexpand(:(@invisible(a=1)))
quote # none, line 3:
a=1 # line 4:
nothing
end
but then I get an error message:
julia> @invisible(a=1)
ERROR: unsupported or misplaced expression kw
so obviously I am not getting something, can someone please help me out?
Also, is there a tutorial or guide on Julia macros that is written for
those familiar with the LISP family, so that I could map concepts in the
two languages?
Best,
Tamas
