chore: group declarations when printing module

[matt2e]

#1089

Ordering and spacing is the following (example has 2 of each declaration type)

{
   config
   config
   secret
   secret

   database
   database

   enum

   enum

   data

   data

   verb

   verb
}

Full example:

module echo {
  config default String
  config default2 String
  secret default3 String
  secret default3 String

  // An echo request.
  data EchoRequest {
    name String? +alias json "name"
    inner echo.EchoRequest2 +alias json "inner"
  }

  data EchoRequest2 {
    name String? +alias json "name"
  }

  data EchoResponse {
    message String +alias json "message"
    inner echo.EchoResponse2 +alias json "inner"
  }

  data EchoResponse2 {
    message String +alias json "message"
  }

  // Echo returns a greeting with the current time.
  verb echo(echo.EchoRequest) echo.EchoResponse  
      +calls time.time

  verb echo2(echo.EchoRequest) echo.EchoResponse  
      +calls time.time
}

[alecthomas]

s/interface{}/any/g

[wesbillman]

@alecthomas do you know if this is "lintable" It might be a good check for the other TBD team as well. :)

[alecthomas]

Declarations should already be sorted in the correct order, so you could simplify this considerably by just iterating over them and printing the correct spacing as you transition between groups/lines.

[matt2e]

Updated to trust the exisiting order, and use reflect.Type rather than empty structs which makes it easier to access rules from the mapping

[alecthomas]

Nice!