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1696 :: How to get the declared type of the field in macro?

• vega (orginal) [2015-10-05T13:16:16+02:00] view original

  Here is the code:

  
  import macros, times, strutils
  
  type Data* = object
    value*: int
    fvalue*: float
    tvalue*: Time
  
  iterator objfields(t: typedesc): (NimNode, NimNode) =
    let reclist = t.getType[1]
    for i in 0..len(reclist)-1:
      echo reclist[i].getType.treeRepr
      yield (reclist[i], reclist[i].getType)
  
  macro test(): stmt =
    result = newStmtList()
    for n, t in Data.objfields:
      let i = $n
      let i2 = $t
      let s = quote do:
        echo `i`, ", ", `i2`
      result.add(s)
  
  test()
  
  Run

  It works with simple type fields (value, fvalue). But it fails with error

  
  Error: unhandled exception: false Invalid node kind nnkBracketExpr for macros.`$`
  Run

  for field tvalue. After adding echo to the iterator, it shows this types for fields:

  
  Sym "int"
  Sym "float"
  BracketExpr
    Sym "distinct"
    Sym "int"
  Run

  How can I get Sym "Time" for tvalue field in this example?

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• vega (orginal) [2015-10-06T09:34:33+02:00] view original

  And if the type of the field is generic, for example Option[int], how do I know it in macro?

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