Author background

• Would you consider yourself a novice, intermediate, or experienced Go programmer?
  • I consider myself an intermediate Go programmer.
• What other languages do you have experience with?
  • I have experience with C/C++, Python before Go.

Related proposals

• Has this idea, or one like it, been proposed before?
  • No.
  • If so, how does this proposal differ?
• Does this affect error handling?
  • No.
  • If so, how does this differ from previous error handling proposals?
• Is this about generics?
  • No.
  • If so, how does this relate to the accepted design and other generics proposals?

Proposal

• What is the proposed change?
  • Add common function of convert IP range to CIDR(s) in net/ip.go. BTW, Python already has such function in netaddr.iprange_to_cidrs(startIP, endIP).
• Who does this proposal help, and why?
  • Network programmer will benefit from this change. Because they can convert IP range to CIDR(s) easily just by call net.ConvertIPRangeToCIDRs.
• Please describe as precisely as possible the change to the language.
  • This proposal will provide more support for IP and CIDR. We do not have the power to convert IP range to CIDR(s) in Go before. With this propasal, for example, [192.168.1.0, 192.168.1.255] can be converted to [192.168.1.0/24], [192.168.1.0, 192.168.1.254] can be converted to [192.168.1.0/25 192.168.1.128/26 192.168.1.192/27 192.168.1.224/28 192.168.1.240/29 192.168.1.248/30 192.168.1.252/31 192.168.1.254/32]. As more and more network related projects are choosing Go as their developing language, I think we do need this change and benefit them.
• What would change in the language spec?
  • No change in language spec.
• Please also describe the change informally, as in a class teaching Go.
  • With this change, we can convert IP range to CIDR(s) by call net.ConvertIPRangeToCIDRs(beginIP, endIP) like this.
• Is this change backward compatible?
  • Yes, this change is backward compatible.
  • Breaking the Go 1 compatibility guarantee is a large cost and requires a large benefit.
    Show example code before and after the change.
  • Before
  • After
• Orthogonality: how does this change interact or overlap with existing features?
  • This change will call existing function under net package to parse IP address as I want to provide simple strings as params in order to be convenient for use.
• Is the goal of this change a performance improvement?
  • No.
  • If so, what quantifiable improvement should we expect?
  • How would we measure it?

Costs

• Would this change make Go easier or harder to learn, and why?
  • This change will make Go easier to use for network programmer. Because this change provide a common function for convert IP range to CIDR(s).
• What is the cost of this proposal? (Every language change has a cost).
  • The size of net/ip.go will increase.
• How many tools (such as vet, gopls, gofmt, goimports, etc.) would be affected?
  • No tool would be affected.
• What is the compile time cost?
  • Not sure.
• What is the run time cost?
  • Not sure.
• Can you describe a possible implementation?
  • Enum every possible CIDR that the IP range can contain, choose the CIDR with max IP addresses as the result. This is implemented by DFS(Deep First Search) algorithm. There is an existing implementation by me. You can refer to github.com/coopersong/irtc. Now I want to move this part to net/ip.go.
• Do you have a prototype? (This is not required.)
  • No.