Hacker News Reader

Comment by throwaway894345 | Hacker News Reader

Yeah, I'm pretty sure there are exactly two substantive problems with JSON for (static) configuration file use cases, which are comments and multiline strings (especially with sane handling of indentation). YAML fixes these, but it adds so much complexity in the process including such a predictable footgun of unquoted strings (the no/false problem is particularly glaring/absurd, but it's also easy to forget to quote other boolean values or numbers in a long list of other strings).

View on HN

Solutions abound, but one option is to use either Javascript (config.js):

    // comments!
    ({
       no_quotes: [1, 2, (() => /* code! */)()],
       ...
     })

Or, let the whole thing be a function. Then your config can have parameters, maybe mapped from environment variables or something.

    ({foo, bar, ...kwargs}) => ({
      datacenter: foo === 'old' ? 'useast1' : 'uswest',
      ...
     })

Can do as Crockford says, and write in the JSON subset of Javascript, but with comments, and convert it to JSON by running it through a JS minifier. I think you need parens around the object, though, or else it looks like a code block (boooo...):

    ({
      // This is very much like JSON
      "foo": [1, 2, "bar"]
     })

Python also has JSON-like syntax, so you could use config.py:

    {
      'foo': [1, 2, 'bar']
    }

That would require a wrapper script. Or, you can have the self-contained convention:

    import json
    import sys
    
    # Yay, comments!
    json.dump({
      # more comments!
      'foo': [1, 2, 'bar']
    }, sys.stdout)

Yeah, I'm mostly just not sure I want to put a full programming language interpreter in my application, especially Python which is not designed to be embeddable. Moreover, I would really want something that is typed, like TypeScript, but libraries for embedded TypeScript interpreters are even more rare :/.

I figure we'd leave it to the build/deploy/CI/development whatever system. I also don't want to extend or embed my application with a full-blown runtime if I don't have to.

"source" config --> convert to JSON config "on the fly" --> app that expects JSON

edit: I worked on a C++ team that used `std::system` to invoke the system python interpreter when loading a config file. My teammates weren't morons, either, it's just the simplest thing that worked and they knew that the config script and the surrounding file system were secure.

Or you can produce Configuration with nix

Can I add "trailing commas are invalid" to the list?

Please do.

json5 is pretty good, if you can use it

Reply on news.ycombinator.com