> > How can I return #undef from a function? You will have to modify the internals of Julia so that *#undef* becomes a value that can be passed around. Currently it isn't, but we have a new concept in 0.4-dev with nullable types <http://docs.julialang.org/en/latest/manual/nullable-types/> that might suit your need.
Ivar kl. 14:27:02 UTC+2 torsdag 9. oktober 2014 skrev David van Leeuwen følgende: > > Hi, > > I am trying to implement type of Array where the values are indexed, i.e., > the value of `a[i]` is `a.value[a.array[i]]`, with `a.value` the discrete > set of values and `a.array` the indices. In the end it should look like > the element type of `a` is just the element type of `a.value`. > > For functions like similar() I would want to be able to return values > #undef to `getindex(a, ...)`, e.g., by setting a.array[:] = 0 indicating > that the array has not been initialized yet. > > How can I return #undef from a function? > > Cheers, > > ---david >
