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7783 :: Opinions on ordering parameters

• jasonfi (orginal) [2021-04-12T18:48:03+02:00] view original

  What are your preferences when ordering parameters of functions? I have found this works for me:

  1. Parameters that are mutable before those that are immutable.
  2. Parameters that are of simple types before those of complex types.
  3. Parameters that are optional after those that are mandatory.

  What's your opinion on this?

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• haxscramper_ (orginal) [2021-04-12T19:13:57+02:00] view original

  I almost never decide based on parameter mutability/immutability, but I've seen people mostly use the following rules (that are partially based on language features, partially on common sense):

  • If you want to use dot syntax for calling, put object of that type as a first parameter. This might be what you ment by "complex types", though only related to the first argument.
  • Optional parameters (with default values) should be put last - this is very common in almost all languages that support default argument values.
  • If you want to pass some parameter as block expression put it last (it might clash [1] with optional parameters, so you need to decide which one is more important)

  proc takesBlock(a: int, blockArg: string) = echo blockArg
  
  
  takesBlock(12):
    "13123"
  Run

  • While it is possible to put arguments after varargs I find this not really intuitive and try to avoid. So put varargs last when possible (and they also clash [1] with optional arguments)
  • Mutability/immutability is not really important for me personally, but things like add, incl, and others of course look better when you use seq.add(element) instead add(element, seq)`. But the difference is not so drasitic I think, so I would advise to decide on case-by-case basis.

  ^[1] By "clash" I mean it might look really strange to the user - for example people might be confused by how variadic: varargs[int], defaulted: int = 2 would be interpreted.

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• SolitudeSF (orginal) [2021-04-12T19:34:18+02:00] view original

  whatever order would feel more natural when calling it. so anything past 2nd argument doesnt really matter.

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• jasonfi (orginal) [2021-04-12T20:09:55+02:00] view original

  Yes, I meant objects by complex types (updated my original question).

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• treeform (orginal) [2021-04-12T23:26:31+02:00] view original

  I do: The main calling object first so that dot syntax looks nice. Then everything else. Then optional parameters. I try to keep things consistent between similar functions. Maybe group similar types together like floats first then booleans. Thats about it. I don't overthink it.

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