# Compute the set of elements composing the border of the core
# Elements belonging to the `border` are removed from the `core`
private fun extract_border do
border.clear
for e in core do
if not is_border(e) then continue
border.add(e)
end
for e in border do core.remove(e)
end
src/compiler/coloring.nit:72,2--81,4