How to handle TomlLazy? about tommy HOT 2 OPEN

Right after posting this, I found that I could check with Table["Key"].IsTable and that would return true only if the key exists, which does solve my problem. I am still curious what the use case for TomlLazy is, however.

from tommy.

Hi, thanks for the question! Glad you managed to find the solution to your question.

TomlLazy is mainly an abstraction over an array or a table that can be automatically created on access. The basic use case is to allow composing TOML files implicitly as such:

var toml = new TomlTable();
toml["array"][0] = "val1";  // toml["array"] returns a TomlLazy instance, but index access [0] automatically replaces TomlLazy with TomlArray
toml["array"][1] = "val2"; // toml["array"] now returns a TomlArray

The basic case is not really interesting, but the TomlLazy becomes useful when you use property initializiers, allowing you to construct the entire table in JSON-like syntax:

var toml = new TomlTable
{
  ["owner"] =                // Here TomlLazy is implicitly created 
  {
     ["name"] = "Foo",   // Here, TomlLazy is implicitly replaced with a TomlTable
     ["dob"]  = "bar",
  },
  ["array"] = { [0] = 1, [1] = 2 }  // Same thing, but now TomlArray is created because of index access
};

This pattern was originally taken from SimpleJSON which at some point was a fairly popular JSON parser/writer for Unity games back when C# did not have.

Nowadays, I'd say that this implicit behaviour is somewhat cryptic, and it belongs to a separate library. Alas, I think it's a breaking change to remove it.

PS: TomlNode has a HasKey method to check whether it contains a key of certain name. If I understood your usecase correctly, Table.HasKey("Key") should do the trick.

from tommy.