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5806 :: Newbie question: Why am I getting the too many variables error on my loop index variable?

• freeflow (orginal) [2020-01-12T23:11:20+01:00] view original

  Couldn't render post #35983.

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• sky_khan (orginal) [2020-01-13T03:56:59+01:00] view original

  if that "split(',')" is from strutils, it returns seq[string], not tuple. I guess you need to use something like this:

  for line in readFile(day02PathAndName):
    var data = line.split(',')
    if data.len() == 2:
      myKey = data[0]
      myValue = data[1]
      result...
    else:
      echo "Error in input: ", line
  Run

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• SolitudeSF (orginal) [2020-01-13T08:56:35+01:00] view original

  there is no split iterator that returns two values at a time. you're confusing it with sequence and implicit pairs. you have to keep track of the indexes on your own here.

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• freeflow (orginal) [2020-01-13T10:59:03+01:00] view original

  On further reading it seems there is a split proc and a split iterator. The former returns a sequence of substrings. The code I have seems to be using the iterator version. How would I indicate to nim to use the proc rather than the iterator version of split?

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• SolitudeSF (orginal) [2020-01-13T12:55:32+01:00] view original

  invoke items/pairs iterator explicitly

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• sky_khan (orginal) [2020-01-13T14:12:22+01:00] view original

  Sorry for being lazy earlier and for my poor English. What I meant was this:

  import strutils
  
  var
    file = """
      Hello,World
      Key,Value
    """
  
  for line in file.split("\n"): # iterator returns string
    var data = line.split(",") # proc returns seq[string]
    # but there is no version of split you can use as "for myKey, myValue in"
    if data.len() == 2:
      echo data[0]," = ", data[1]
  
  Run

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• freeflow (orginal) [2020-01-13T16:16:26+01:00] view original

  I'll have to wait until my knowledge of nim improves before I can that. In the meantime I'm using

  let mySeq:seq[string]=readFile(day02PathAndName).split(',')
  for myKey, myValue in  mySeq:
      result[myKey.int64]=myValue.parseint.int64
  Run

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• Araq (orginal) [2020-01-13T16:17:14+01:00] view original

  Seems to be a use-case for Nim's csv parser, https://nim-lang.org/docs/parsecsv.html

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• freeflow (orginal) [2020-01-13T16:54:24+01:00] view original

  It might be more productive if I advise you that I spent several days perusing the nim documentation before I admitted defeat and asked a question here. @Solitude's comments highlighted something that is not adequately referenced when you read the for loop section of the manual.

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• freeflow (orginal) [2020-01-13T17:10:23+01:00] view original

  Aha: success

  for myKey, myValue in  readFile(day02PathAndName).split(',').pairs():
      result[myKey.int64]=myValue.parseInt
  Run

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