I’m doing some exhaustive search loops and would like to cover say a range 10:100 but suspect (with quite some confidence) that the solution I look for is around 90. So I would like to loop over the range by starting at 90 and looking around to be possibly be able to break early: 90, 91,89,92,88,93,87,94,86,95,85,96,84,97,83,98,82,99,81,100,80, 79, … 10

I guess defining a custom iterator would be the best solution, but I’m not very familiar with it. Any suggestion what to be careful about if I launch myself into this?
Thanks in advance

julia> struct RangeAround{R1,R2}
lower::R1
upper::R2
function RangeAround(range::R, start) where R
i = findfirst(==(start), range)
i === nothing && error("Start point $start not in range $range")
lower = reverse(range[begin:i])
upper = range[i+1:end]
new{typeof(lower), typeof(upper)}(lower, upper)
end
end
julia> Base.iterate(a::RangeAround) = (first(a.lower), 2)
julia> function Base.iterate(a::RangeAround, i)
length_upper = length(a.upper)
length_lower = length(a.lower)
if i > length_upper + length_lower
return nothing
else
shared_length = min(length_upper, length_lower)
if i <= 2 * shared_length
return iseven(i) ? a.upper[i ÷ 2] : a.lower[(i + 1) ÷ 2], i + 1
elseif length_upper > length_lower
return a.upper[i - shared_length], i + 1
else
return a.lower[i - shared_length], i + 1
end
end
end