Mirror of forum.nim-lang.org

498 :: Multidimensional sequences and openarrays

• fuzzthink (orginal) [2014-07-16T23:31:27+02:00] view original

  Can sequence be multidimensional? If so, how is a 2d sequence type defined and used?

  Also, since openarrays can't be multidimensional, how is its usage (2d indexing via multiplication) performance compared to a 2d sequence (if sequences can be multidimensional)?

---

• leledumbo (orginal) [2014-07-17T00:38:29+02:00] view original

  Can sequence be multidimensional? If so, how is a 2d sequence type defined and used?

  
  type
    TMy2DSeq = seq[seq[int]]
  
  var
    x = @[@[1],@[1,2],@[1,2,3]]
  Run

  > Also, since openarrays can't be multidimensional, how is its usage (2d indexing via multiplication) performance compared to a 2d sequence (if sequences can be multidimensional)?

  I'm not quite sure, but a flat memory should always be faster than 2D pointer indexing.

---