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1745 :: proc returning a type seq[T]

• rob10c (orginal) [2015-10-28T18:43:14+01:00] view original

  as i could pass any single object parameter to be modified within a proc, or try to assign a proc to a (single)variable why the last example compiles but the content is nil.

  #void
  proc modifySeq(mySeq: var seq[int]) =
    mySeq[9] = 999
  
  
  # string simple works
  proc crStr(): string =
      "doing c"
  # does not work in this way
  proc crePopulatSeqStr(parSz: int): seq[string] =   #started with a builtin type
    result = newSeq[string](parSz)
    for i in 0..parSz:
      result.add("do f-" & $i)
  
  echo crePopulatSeqStr(10)[0]

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• andrea (orginal) [2015-10-28T19:07:47+01:00] view original

  You are creating a seq of length parSz (filled with nil) and then appending to it.

  What you want to do is start from an empty seq and append, or create the seq of the given length and then assign to the existing slots (instead of appending).

  That is, this will work

  proc crePopulatSeqStr(parSz: int): seq[string] =   #started with a builtin type
    result = @[]
    for i in 0.. < parSz:
      result.add("do f-" & $i)
  Run

  and this will as well

  proc crePopulatSeqStr(parSz: int): seq[string] =   #started with a builtin type
    result = newSeq[string](parSz)
    for i in 0.. < parSz:
      result[i] = "do f-" & $i
  Run

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• rob10c (orginal) [2015-10-29T00:24:45+01:00] view original

  thanks andrea i'll try this

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