readwritepointer.js

# julia -i readwritepointer.js

type keyboard_s
  forward::Int32
  backward::Int32
  left::Int32
  right::Int32
  jump::Int32
end
address = ccall(:malloc, (Int64), (Int64, ), sizeof(keyboard_s))
ptr = Ptr{keyboard_s}(address)

# this code shall change the actual malloc()ed memory, but it basically just makes a copy instead
thekeyboard_a = unsafe_load(ptr)
thekeyboard_a.forward = 123 # this has no effect on the real memory address :(
# read the pointer again, same address, "forward" have the value 123
thekeyboard_b = unsafe_load(ptr)
if thekeyboard_a.forward == thekeyboard_b.forward
  print("works!\n")
else
  print("doesnt work!\n")
end