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3490 :: How to pass a int to a matrix like: Matrix[W,H:static[int]] ?

• Felipe (orginal) [2018-01-19T21:46:05+01:00] view original

  I've the following code:

  import random,strutils,rdstdin
  
  type
    Matrix[W,H:static[int]]=
      array[1..W,array[1..H,int]]
  
  proc RandMatrix(w,h,r1,r2:int):auto=
    var
      mat:Matrix[w,h]
    for i in 1..w:
      for j in 1..h:
        mat[i][j]=rand(r1..r2)
    return mat
  
  var
    w,h,r1,r2:int
  
  w = parseInt(readLineFromStdin "W: ")
  h = parseInt(readLineFromStdin "H: ")
  r1 = parseInt(readLineFromStdin "R1: ")
  r2 = parseInt(readLineFromStdin "R2: ")
  
  var
    mat=RandMatrix(w,h,r1,r2)
  
  for i in 1..w:
    for j in 1..h:
      stdout.write mat[i][j]
      echo  ""
  Run

  At the RandMatrix function, I declared:

  var mat:Matrix[w,h]
  Run

  But w,h are int, and the Matrix type just accept static[int], how can I solve that? I just tried to exchance static[int] for int, but without any success.

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• Stefan_Salewski (orginal) [2018-01-19T22:32:03+01:00] view original

  I think your main problem is, that Nim's arrays have fixed compile time size, but you try to specify size at runtime by values read from keyboard. For a dynamic size container you can use seq data type, for a matrix a seq where each element is again a seq.

  To get an idea you may compare

  https://stackoverflow.com/questions/30298950/initialize-a-seq-of-seqs

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• Udiknedormin (orginal) [2018-01-27T09:03:31+01:00] view original

  Better yet, use a single seq and iterate over it as if it was NxM. It will be more cache-friendly.

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