Can I have a Mapping on a Class at the top level?

[kaihendry]

My config.pkl looks like:

outputs {
  new {
    name = "Foo deployment"
    ["dev"] {
      bucketName = "foo-dev"
    }
    ["prd"] {
      bucketName = "foo-prd"
    }
    ["uat"] {
      bucketName = "foo-uat"
    }
  }
   new {
    name = "Bar deployment"
    ["dev"] {
      bucketName = "bar-dev"
    }
    ["prd"] {
      bucketName = "bar-prd"
    }
    ["uat"] {
      bucketName = "bar-uat"
    }
  }
}

My schema.pkl doesn't config the top level mappings!

open module demo

typealias ENV = "dev"|"int"|"uat"|"prd"

class OutputPort {
    name: String
    Mapping<ENV, Deployment> // doesn't work!
}

class Deployment {
    bucketName: String
}

outputs: Listing<OutputPort>

[HT154]

You cannot have a class "merged" with a Mapping. The Mapping must be a particular property of the class:

class OutputPort {
    name: String
    deployments: Mapping<ENV, Deployment>
}

That said, in this case the valid Mapping keys are known ahead of time so you might consider "promoting" them to being nullable properties on the class instead:

class OutputPort {
    name: String
    dev: Deployment?
    int: Deployment?
    uat: Deployment?
    prd: Deployment?
}

[StefMa]

It would probably be possible with your own renderer though...

[HT154]

Something like this:

open module demo

typealias ENV = "dev"|"int"|"uat"|"prd"

class OutputPort {
    name: String
    deployments: Mapping<ENV, Deployment>
}

class Deployment {
    bucketName: String
}

outputs: Listing<OutputPort>

output {
  renderer {
    converters {
      [OutputPort] = (it) -> new Dynamic {
        ...it.toMap().remove("deployments").toDynamic()
        ...it.deployments
      }
    }
  }
}

[StefMa]

I guess not quite what he want... 🤔

open module demo

typealias ENV = "dev"|"int"|"uat"|"prd"

class OutputPort {
    name: String
    deployments: Mapping<ENV, Deployment>
}

class Deployment {
    bucketName: String
}

outputs: Listing<OutputPort> = new {
  new {
    name = "test"
    deployments = new {
      ["dev"] = new {
        bucketName = "bktname"
      } 
    }
  }
}

output {
  renderer {
    converters {
      [OutputPort] = (it) -> new Dynamic {
        ...it.toMap().remove("deployments").toDynamic()
        ...it.deployments
      }
    }
  }
} 

Output as json:

{
  "outputs": [
    {
      "name": "test",
      "dev": {
        "bucketName": "bktname"
      }
    }
  ]
}

Output as pcf:

outputs {
  new {
    name = "test"
    ["dev"] {
      bucketName = "bktname"
    }
  }
}

So yes, the output works. But he wants thst as input 🙃.

The only solution is to go with Dynamic as template. But limit this with an custom renderer. But I guess the whole typing is destroyed with this solution. So I guess it's rather a "it's not possible with strong typing".

[kaihendry]

Not sure if you tried your code samples, but neither approach seems to work:

pkl eval -f yaml config.pkl | tee config.yml
–– Pkl Error ––
Object of type `demo#OutputPort` cannot have an entry.

6 | ["dev"] {
     ^^^^^
at config#outputs[#1] (file:///Users/hendry/tmp/pkl-env/config.pkl, line 6)

Only objects of type `Mapping` and `Dynamic` can have entries. If you did not mean to add an entry, you probably got the syntax wrong. For example, `obj { ["name"] = "Pigeon" }` adds an entry, whereas `obj { name = "Pigeon" }` sets a property.

106 | text = renderer.renderDocument(value)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
at pkl.base#Module.output.text (https://github.com/apple/pkl/blob/0.28.2/stdlib/base.pkl#L106)

[HT154]

Neither of my suggestions do what you want because that's not possible. In both cases your config would need a slightly different structure.

The first suggestion entails putting your entries under a nested property:

outputs {
  new {
    name = "Foo deployment"
    deployments {
      ["dev"] {
        bucketName = "foo-dev"
      }
      ["prd"] {
        bucketName = "foo-prd"
      }
      ["uat"] {
        bucketName = "foo-uat"
      }
    }
  }

The second would use properties instead of mapping entries:

outputs {
  new {
    name = "Foo deployment"
    dev {
      bucketName = "foo-dev"
    }
    prd {
      bucketName = "foo-prd"
    }
    uat {
      bucketName = "foo-uat"
    }
  }