You can use the esc
<http://julia.readthedocs.org/en/latest/stdlib/base/?highlight=esc#Base.esc>
function
that can introduce variables in the calling environment
julia> type Point
x
y
end
julia> macro fetch(p)
variables = quote
x = $p.x
y = $p.y
end
return esc(variables)
end
julia> p = Point(5, 10)
Point(5,10)
julia> x
ERROR: x not defined
julia> y
ERROR: y not defined
julia> @fetch p;
julia> x
5
julia> y
10
On Saturday, June 7, 2014 2:35:59 AM UTC-5, Andrew Simper wrote:
>
> A lot of the time it is good to copy a structure to local variables and
> then process on those for efficiency before storing the local values back
> to a structure. To help out with this I'm trying to write a macro, so this
> is what I would like the end result to be:
>
> Point
> x::Float64
> y::Float64
> end
>
> function process (p::Point)
> local x = p.x;
> local y = p.y;
> # do some processing on x and y
> p.x = x
> p.y = y
> end
>
> and I would like write a macro that does this so the end code would like
> like:
>
> function process (p::Point)
> @fetch p
> # do some processing on x and y
> @store p
> end
>
> So far I've got this working at the REPL using:
>
> point = Point (1, 2)
> map (eval, ([:($name = point.$name) for name in names(point)]))
> println("x=$(x) y=$(y)")
>
> which prints out: x=1.0 y=2.0
>
> Can someone please help out turning this into a macro?
>
>
