Spiral iteration

[cormullion]

Hi! Don't know if this package is still being maintained, but I was interested to trying to understand how the spiral iteration works. I can't understand the error message I get:

using  Hexagons

h = hexagon(1, 2)

# this works

println("neighbors")
for n in neighbors(h)
    @show n
end 

# this works
println("ring")
for n in ring(1, h)
    @show n
end

# but this errors

println("spiral")
for n in spiral(1, h)
    @show n
end

ERROR: UndefVarError: start not defined
Stacktrace:
 [1] iterate(it::HexagonSpiralIterator)
   @ Hexagons ~/.julia/packages/Hexagons/qn1vZ/src/Hexagons.jl:295
 [2] top-level scope
   @ ./Untitled-1:21