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7580 :: template - Error: in expression 'p.some(n)': identifier expected, but found 'some(n)'

• mantielero (orginal) [2021-03-04T20:26:56+01:00] view original

  I have a template like:

  template register*( val: float;
                      caus:Option[Causality] = none(Causality); #cLocal;
                      varia:Option[Variability] = none(Variability); #vContinuous;
                      ini:Option[Initial] = none(Initial); #iUnset;
                      desc:Option[string] = none(string);
                      derivative:Option[uint] = none( uint );
                      start: Option[float] = none(float) ) {.dirty.} =
    if val.type.name == "float":
      var p = Param(kind: tReal)
      p.name = val.astToStr
      p.idx = nParamsR
      p.addressR = addr(val)
      p.causality = caus
      p.variability = varia
      p.initial = ini
      p.description = desc
      
      p.derivative = derivative
      p.start = start.get
      
      static: nParamsR += 1
      params.add p
  Run

  and when I call it with:

  fmu( "dq", "{8c4e810f-3df3-4a00-8276-176fa3c9f000}"):
    var x:float = 1.0
    register( x,     caus = cLocal.some,
              varia =   vContinuous.some, ini = iExact.some,
              desc =     "the only state".some,
              derivative = 0.uint.some )
  Run

  I get the error:

  
  Error: in expression 'p.some(n)': identifier expected, but found 'some(n)'
  Run

  on the line that contains: derivative = 0.uint.some.

  What could be the reason?

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• mratsim (orginal) [2021-03-04T21:18:16+01:00] view original

  This is with template substitution this line

  
  p.derivative = derivative
  Run

  becomes

  
  p.0.uint.some = 0.uint.some
  Run

  Don't name your template parameter the same as an object field.

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• ynfle (orginal) [2021-03-04T21:18:35+01:00] view original

  What is the surrounding context besides import options

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• mantielero (orginal) [2021-03-04T21:31:21+01:00] view original

  @mratsim well spotted. I was becoming crazy!

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• Araq (orginal) [2021-03-04T22:14:47+01:00] view original

  It's a common gotcha but it's also hardly fixable, using templates to abstract over field names is an important capability. In your case you can simply use an inline proc though. Also, use the object constructor syntax instead of this mess of assignments -- esp under Orc object constructors generate better code.

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