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6432 :: Can't access fields of object returned by a procedure

• ameerwasi (orginal) [2020-06-14T08:27:15+02:00] view original

  Sorry, if this sounds a bit idiotic because I started using nim yesterday, so my problem is that I created a type such as what follows

  import position
  
  type
    Error* = object
      pos_start : position.Position
      pos_end : position.Position
      name: string
      details: string
  Run

  then I went on to create a procedure that returns an instance of this type,

  proc IllegalCharacterError*(pos_start : position.Position, pos_end : position.Position, details : string) : Error =
    return Error(pos_start: pos_start, pos_end: pos_end, name: "IllegalCharacterError", details: details)
  Run

  Now, everything works fine except when I, from another module, try to access fields of this returned instance I get error

  from errors import nil
  from position import nil
  
  var current_char = "2"
  let pos = position.Position(idx: -1, ln: 0, col: -1, fn: fn, ftxt: text)
  let error = errors.IllegalCharacterError(pos, pos, current_char)
  echo error.name
  Run

  The last line is the one that throws the error and following is the error that appeared during compilation

  
  Error: undeclared field: 'name' for type errors.Error [declared in C:\Users\Mlogix\Desktop\testNim\errors.nim(4, 3)]
  Run

  Thanks, any help would be really appreciated.

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• ameerwasi (orginal) [2020-06-14T08:58:21+02:00] view original

  For anyone visiting, I just had to make my fields public and everything worked. This is the code, I changed

  import position
  
  type
    Error* = object
      pos_start* : position.Position
      pos_end* : position.Position
      name*: string
      details*: string
  Run

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• Araq (orginal) [2020-06-15T09:27:43+02:00] view original

  Anytime soon now (ha!) we'll improve the error message for this, it's a common gotcha for newcomers.

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• treeform (orginal) [2020-06-15T17:13:07+02:00] view original

  For oldcommers too! Error should say x is not public, not that x is missing.

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