[Feature Request] Support YAML for podspec and JSON for Podfile

[Whirlwind]

I found that, the Podfile support ruby and yaml, not the json, but the podspec support ruby and json, not the yaml.

The Podfile:

    def self.from_file(path)
      path = Pathname.new(path)
      unless path.exist?
        raise Informative, "No Podfile exists at path `#{path}`."
      end

      case path.extname
      when '', '.podfile', '.rb'
        Podfile.from_ruby(path)
      when '.yaml'
        Podfile.from_yaml(path)
      else
        raise Informative, "Unsupported Podfile format `#{path}`."
      end
    end

The podspec:

    def self.from_string(spec_contents, path, subspec_name = nil)
      path = Pathname.new(path).expand_path
      spec = nil
      Dir.chdir(path.parent.directory? ? path.parent : Dir.pwd) do
        case path.extname
        when '.podspec'
          spec = ::Pod._eval_podspec(spec_contents, path)
          unless spec.is_a?(Specification)
            raise Informative, "Invalid podspec file at path `#{path}`."
          end
        when '.json'
          spec = Specification.from_json(spec_contents)
        else
          raise Informative, "Unsupported specification format `#{path.extname}` for spec at `#{path}`."
        end
      end

      spec.defined_in_file = path
      spec.subspec_by_name(subspec_name, true)
    end

I known it is not a important feature for using same format, but I still create this issue. Has Somebody free time to add the format support?

[Whirlwind]

By the way, the command line could convert podfile to yaml, but could not convert the podspec to yaml:

Usage:

    $ pod ipc COMMAND

      Inter-process communication

Commands:

    + list                  Lists the specifications known to CocoaPods
    + podfile               Converts a Podfile to YAML
    + podfile-json          Converts a Podfile to JSON
    + repl                  The repl listens to commands on standard input
    + spec                  Converts a podspec to JSON
    + update-search-index   Updates the search index

[dnkoutso]

JSON for Podfile was discussed and reject here #545

[Whirlwind]

I think it is strange that I could get the json from Podfile and could not pass the json to Cocoapods.

And the podspec is same.

[orta]

We built pod ipc podfile-json for the CocoaPods Mac app I believe, which didn't need to read JSON podfiles, but as a GUI it was very useful to get a JSON equivalent.

[Whirlwind]

Yes, I agree that. I have an app to handle the cocoapods, it likes CocoaPods Mac app. But I have a feature to generate the Podfile, and read it. It is too slow to pod ipc podfile-json, and it hard to write a Podfile( it is a ruby script ). I could not use some model tools ( eg: JSONModel ).

For example, I use the yaml formatter for Podfile, and use the json formatter for podspec. I must have two libraries to handle them. Of cause, it is not too hard, but I think it is very strange.