local function getSuccessors( q )
	local successors = {}
	local region     = region.getAtPosition( q )
	local x, y       = q.x, q.y
	local w, h       = region:getTileSize()

	local directions = {
		[ 1 ] = node( x, y - h ), -- North
		[ 2 ] = nil,
		[ 3 ] = node( x + w, y ), -- East
		[ 4 ] = nil,
		[ 5 ] = node( x, y + h ), -- South
		[ 6 ] = nil,
		[ 7 ] = node( x - w, y )  -- West
	}

	if ( getDirections() == 8 ) then
		merge( directions, {
			[ 2 ] = node( x + w, y - h ), -- North East
			[ 4 ] = node( x + w, y + h ), -- South East
			[ 6 ] = node( x - w, y + h ), -- South West
			[ 8 ] = node( x - w, y - h )  -- North West
		} )
	end

	for _, position in ipairs( directions ) do
		if ( region:isTileWalkableAtPosition( position ) ) then
			insert( successors, position )
		end
	end

	return successors
end