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8842 :: convert HSlice to varargs?

• oyster (orginal) [2022-01-26T07:29:53+01:00] view original

  as we know

  import bitOps
  
  var x = 1'u8
  x.setBits(0, 1, 2, 3)
  echo x
  Run

  says 15

  and we can use HSlice to get the same result:

  var x = 1'u8
  for i in 0 .. 3:
      x.setBits(i)
  echo x
  Run

  but we can't use x.setBits(0 .. 3) directly. So is there a way to unpack an HSlice to be use as varargs? In python, a list can be used like this

  Run

  which says 1 2 3

  thanks

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• MichalMarsalek (orginal) [2022-01-26T07:39:14+01:00] view original

  I don't remember if seq can be used in place of varargs. If so, toSeq should work.

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• DavideGalilei (orginal) [2022-01-26T07:49:08+01:00] view original

  Unfortunately, x.setBits(@[0, 1, 2, 3]) doesn't work for me. It is possible to use bitwise operations, though:

  
  var x = 1'u8
  let range = 0 .. 3
  x = x or ((1'u8 shl len(range)) - 1'u8)
  echo x # 15
  Run

  Note that this only works if range looks like 0 .. n, and would require further modification to work with ranges like 4 .. 7.

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• sls1005 (orginal) [2022-01-26T13:21:21+01:00] view original

  You may overload it.

  proc setBits(x: var uint8, hs: HSlice) =
    for i in hs:
      x.setBits(i)
  Run

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