5 ms·

Not a popular answer, but XML is mature, widely supported by many programming languages, and addresses all of the frustration criteria mentioned in the article:

Not a popular answer, but XML is mature, widely supported by many programming languages, and addresses all of the frustration criteria mentioned in the article: - doesn't have comments XML uses the same  SGML-style comments that HTML does - bits of configs can't be reused XML can include other XML via XInclude: https://www.w3.org/TR/xinclude/ https://www.w3.org/TR/xinclude/ - can't contain any logic You can technically put logic in XML using XSLT (https://www.w3.org/TR/2017/REC-xslt-30-20170608/ https://www.w3.org/TR/2017/REC-xslt-30-20170608/), but I would ask if one SHOULD put logic into your configuration. I personally would recommend against it if at all possible. Keep configuration as declarative as possible and put the logic in your program. It's better to have a configuration logic module or use dependency injection than put logic in your config. - Programming language constructs are reinvented from scratch Again, XSLT could be used, but should your configuration really need to be Turing-complete? Granted, XML is complicated and not without criticisms, but it is mature, standardized, and well-supported. Python has great XML support: https://docs.python.org/3/library/xml.html https://docs.python.org/3/library/xml.html - can't be validated XML can be validated against XML Schema (https://www.w3.org/XML/Schema https://www.w3.org/XML/Schema), Relax NG (https://relaxng.org/ https://relaxng.org/), and possibly other standards. - implicit conversions and portability issues XML can be used portably between different platforms and programming languages depending on how the data is represented. XML Schema defines a way to describe data types that is flexible and interoperabile: https://www.w3.org/TR/xmlschema-2/ https://www.w3.org/TR/xmlschema-2/ Again, I know it's not the popular answer, but I was surprised that it was not even mentioned in the article.

q3k 7y ago
The main reason I'm not using XML seriously is that it only really has a single native, scalar type: string. Sure, you can schema validate away a large part of this problem, but it's still somewhat of a wart.
dirtydroog 7y ago
XML needs to die
mdaniel 7y ago
Merely for your consideration, I suspect a lot of people have opposition to XML because it is noisy when edited by a human: <httpd> <baseDir>/opt/server</baseDir> </httpd> Of that snippet, "</baseDir>" and "</httpd>" are characters of my life that I will never get back, since they're just parser niceities and not _value_ Moving up the enlightenment chain: {"httpd": {"baseDir": "/opt/server"}} or its brace-and-quoteless friend: httpd: baseDir: /opt/server place a lot more emphasis on the payload and less on the packaging
- thesuperbigfrog 7y ago
  It is a matter of preference and legibility. With XML and other "fully qualified" syntaxes the named closing tag makes it easy to visually see where a block starts and stops. Humans parse the text too. This begs the question: Do you read config more or do you write config more? Braces and parens all look the same, so its harder to visually match them. "But wait," you may say, "my editor / IDE does brace and paren matching so I can easily see and jump to the corresponding brace or paren." True, but doesn't your editor / IDE also support or have plugins for automatic HTML / XML end tag insertion? Personally, I am equally comfortable with XML and JSON style configuration, but I find the brace-and-quoteless style unsettling because I believe that whitespace is a poor choice for delimiting structure. Your opinion may vary and that is fine. Do what works best for you.
- benibela 7y ago
  But you can do <httpd baseDir="/opt/server"/> and it is shorter than the JSON.
  - reirob 7y ago
    In my opinion one of the weaknesses of XML is that it gives so many ways to express the same data, in attributes, as nested elements, with CDATA, and probably different other ways. And often it is a matter of taste. So in the end you come up with so many approaches to express similar structures.
    - 7y ago
olodus 7y ago
> Again, XSLT could be used, but should your configuration really need to be Turing-complete? A few of OPs suggestions are not Turing complete, but rather total programming languages as is the case with Dhall.
steerablesafe 7y ago
> You can technically put logic in XML using XSLT (https://www.w3.org/TR/2017/REC-xslt-30-20170608/ https://www.w3.org/TR/2017/REC-xslt-30-20170608/), but I would ask if one SHOULD put logic into your configuration. Well, definitely not XSLT.

q3k 7y ago

The main reason I'm not using XML seriously is that it only really has a single native, scalar type: string. Sure, you can schema validate away a large part of this problem, but it's still somewhat of a wart.

dirtydroog 7y ago

XML needs to die

mdaniel 7y ago

Merely for your consideration, I suspect a lot of people have opposition to XML because it is noisy when edited by a human: <httpd> <baseDir>/opt/server</baseDir> </httpd> Of that snippet, "</baseDir>" and "</httpd>" are characters of my life that I will never get back, since they're just parser niceities and not _value_ Moving up the enlightenment chain: {"httpd": {"baseDir": "/opt/server"}} or its brace-and-quoteless friend: httpd: baseDir: /opt/server place a lot more emphasis on the payload and less on the packaging

thesuperbigfrog 7y ago
It is a matter of preference and legibility. With XML and other "fully qualified" syntaxes the named closing tag makes it easy to visually see where a block starts and stops. Humans parse the text too. This begs the question: Do you read config more or do you write config more? Braces and parens all look the same, so its harder to visually match them. "But wait," you may say, "my editor / IDE does brace and paren matching so I can easily see and jump to the corresponding brace or paren." True, but doesn't your editor / IDE also support or have plugins for automatic HTML / XML end tag insertion? Personally, I am equally comfortable with XML and JSON style configuration, but I find the brace-and-quoteless style unsettling because I believe that whitespace is a poor choice for delimiting structure. Your opinion may vary and that is fine. Do what works best for you.
benibela 7y ago
But you can do <httpd baseDir="/opt/server"/> and it is shorter than the JSON.
- reirob 7y ago
  In my opinion one of the weaknesses of XML is that it gives so many ways to express the same data, in attributes, as nested elements, with CDATA, and probably different other ways. And often it is a matter of taste. So in the end you come up with so many approaches to express similar structures.
  - 7y ago

olodus 7y ago

> Again, XSLT could be used, but should your configuration really need to be Turing-complete? A few of OPs suggestions are not Turing complete, but rather total programming languages as is the case with Dhall.

steerablesafe 7y ago

> You can technically put logic in XML using XSLT (https://www.w3.org/TR/2017/REC-xslt-30-20170608/ https://www.w3.org/TR/2017/REC-xslt-30-20170608/), but I would ask if one SHOULD put logic into your configuration. Well, definitely not XSLT.