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3622 :: The Nim way to do this

• jzakiya (orginal) [2018-03-09T03:22:20+01:00] view original

  I've looked through the docs but haven't found the answer to this.

  I have an array of integers (prime numbers) and I want to: 1) determine if some number is included in the array and 2) return the index value of the number in the array.

  In Ruby/Crystal I can do the following. What are the equivalent method(s) in Nim?

  
  Ruby
  
  1) primes = [7, 11, 13, 17, 19, 23, 29, 31]
  
  if primes.include? num; do_something_here end
  
  2) index = primes.index num
  
  Run

  I tried to do the following in Nim to give me the equivalent result for 1) in Nim, but the compiler squawks.

  
  Nim
  
  1) if count(primes, num) == 1: do_something_here
  
  Run

  I expected that count(primes, num) would return 0 if num isn't in primes but the compiler gives type mismatch error.

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• JohnS (orginal) [2018-03-09T04:18:13+01:00] view original

  let primes = [7, 11, 13, 17, 19, 23, 29, 31]
  
  #1
  if 7 in primes: echo("Found it!")
  
  #2
  echo primes.find(13)
  Run

  I don't think count does what you think it does. According to the docs it "Returns the number of occurrences of the item x in the container s."

  Hope that helps! :D

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• jzakiya (orginal) [2018-03-09T04:31:36+01:00] view original

  Thanks! Where in the docs are these methods?

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• mashingan (orginal) [2018-03-09T05:23:10+01:00] view original

  in is operator in Nim which uses proc contains

  If you want to use the in operator, you should provide binary proc contains .

  Since contains is widely implemented in various stdlib (it's needed to if we want to use in ), you can check from theindex which one you need.

  I suggest you check the contains proc from system module.

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