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Comment by jokull | Hacker News Reader

INI, JSON and YAML all have problems. None of them are serious enough for me to consider this for a small project with one or two config files required. Good to be able to point to a config file syntax done right though.

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But the combination of Tom's reputation and the nightmare security situation currently unfolding with YAML means this project has a very high likelihood of becoming defacto standard in the Ruby community. The thought of being able to get rid of YAML from my code base entirely is an appealing end unto itself. Security aside, YAML is just ridiculously complex and error-prone.

Can you tell at a glance what is wrong with this YAML snippet:

  scandinavia:
    SE: Sweden
    NO: Norway
    FI: Finland

I'm not familiar enough with YAML to see the problem at a glance but parsing the snippet with an online parser [1] suggests that unless you put quotation marks around "NO" it gets parsed into a boolean False. Looks precarious, especially since not requiring strings to be quoted is kind of a selling point of YAML.

[1] https://yaml-online-parser.appspot.com/

That's it, but you cheated :)

I had to spend half an hour debugging a bizarre side effect of that parsing to pinpoint the problem.

That is utterly stupid isn't it, how could the designers of YAML count a capital "NO" as a key as False. Wow.

Edit, holy fuck all these are booleans:

y|Y|yes|Yes|YES|n|N|no|No|NO |true|True|TRUE|false|False|FALSE |on|On|ON|off|Off|OFF

Do tell about the problems with JSON for use as a configuration object? Almost every language has a library that can parse JSON.

It’s hard to author by hand. Ever added a comma after the last element in a list? It’s not very forgiving.

This is actually one of the worst things about it to me, other than the lack of comments. A language that has comma-separated lists and doesn't allow trailing commas on the list as a whole is frustrating to use in a version controlled context because adding an item requires modifying the item before, which leads to more (and less obviously solvable) merge conflicts.

I've seen a style of list initialization that sort of addresses this issue. I like it, but I don't see it used very often. Darn you standards!

    kittyBreeds = ["Himalayan"
                  ,"Bengal"
                  ,"Siamese"
                  ,"Burmese"
                  ,"Cornish Rex" //rawr
                  ,"LaPerm"
                  ,"Manx"  
    
    //This is not a real cat! >:(
    //              ,"lolcat"
                  ,"Munchkin"
                  ,"Ocicat"
                  ];

In this way the issue with the commas is relegated to the first element, rather than the last. Since appending is more common, this seems a better style.

Interesting approach. This strikes me as kind of like the classic "put the constant on the left" advice in C/C++ that, no matter how many people agree it's a good idea, no one ever does because the cognitive effort of understanding it is high enough to diminish the correctness benefit.

In other words, you know you're just gonna end up with this in your code after a few months:

kittyBreeds = ["Himalayan", ,"Bengal", "Siamese", "Cornish Rex", ,"Manx"]

and not only is it now even worse for changing lines (correcting it and adding another will be -1+3 instead of just -1+2, the optimal +1 a distant memory), but it's just plain a mess and probably people don't know why they need to do it.

That's JavaScript not just JSON, if you install JSHint or JSLint in your editor you'll spot the error right away.

I like to put comments in my configuration files. How do you comment out blocks of a JSON configuration file?

Pipe it through JSmin or something else that strips comments.

You seem picky. :) But check out libconfig. Maybe it'll work for you.

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