Support for JSON schema built-in formats

[pierrecdn]

Is your feature request related to a problem? Please describe.

I was wondering if built-in formats from JSON schema specs are implemented in the project.

Answer sounds to be no from what I'm seeing.

Describe the solution you'd like

An implementation of built-in formats, it is very convenient compared to plain regexes.

Describe alternatives you've considered

Regexes, but that's a workaround.

Context

values schema containing such field:

  "dns": {
     "title": "DNS resolver",
     "type": "string",
     "format": "ipv4",
     "description": "The DNS server to use"
  }