A Hilbert curve is a space-filling (snakey) curve through a 2D space:

This can be very useful for mapping a 1D value, into a 2D space. For example, it is commonly used to map IP addresses into a 2D space.

I recently created a library for Go that can map to and from a curve. The project is hosted on Github, and can be used like so:

import"github.com/google/hilbert"// Create a Hilbert curve for mapping to and from a 16 by 16 space.
s,err:=hilbert.New(16)// Now map one dimension numbers in the range [0, N*N-1], to an x,y
// coordinate on the curve where both x and y are in the range [0, N-1].
x,y,err:=s.Map(t)// Also map back from (x,y) to t.
t,err:=s.MapInverse(x,y)

The project contains some demos, such as this cool animations: