[julia-users] Help with writing a macro to for fetch, process, store pattern

[Andrew Simper]

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?