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9887 :: What does the @ symbol do?

• FluxCapacitor (orginal) [2023-02-13T21:40:27+01:00] view original

  Total Nim beginner here. I'm just reading through the Nim basics tutorial and have a super quick question:

  What does the @ symbol do?

  for example:

   a = @[5,6,7,8,9]
  echo a[1]
  Run

  versus without the @ symbol:

   a = [5,6,7,8,9]
  echo a[1]
  Run

  Both seem to work and produce the same output.

  However, here's another example:

   e1: seq[int] = @[]
  e1.add(5)
  echo e1
  Run

  In this case, it only works with the @ symbol and fails to compile without it.

  What's going on here?

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• miran (orginal) [2023-02-14T07:12:30+01:00] view original

  From the arrays chapter:

  Arrays are also of a constant size, meaning that the amount of elements (or rather: the amount of possible elements), must be known at compile-time.

  In other words: you cannot change the size of an array by adding some element to it.

  So, back to your question:

  What does the @ symbol do?

  It converts an array (e.g. [1, 2, 3]) to a sequence (@[1, 2, 3]). From the sequences chapter:

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