Brief Basic Argument Parsing in Nim with comment explanations

parsing.nim

# default variables that could be modified from cmd arguments (if needed /desired)
var portNum: int = 443

# CLI Arguments for the Server
#  in nim argument values must be passed with = or :

# Brief Basic Arugment Parsing in Nim, probably not for production arg parsing
# see documentation page for slightly more details: https://nim-lang.org/docs/parseopt.html
# each argument token has a kind, a key, and val. 
# ... kind being the type of argument, cmdEnd signaling the end of the command line
# ... key being the name
# ... val being the key's value provided or empty string
# getopt: is for iterating over the arguments with it returning the tuple with kind, key, val 
# ... https://nim-lang.org/docs/parseopt.html#getopt
for kind, key, value in getopt(): # we do this because it is a tuple of three returned
  
  # kind (CmdLineKind): this is the type of argument seen, cmdArgument, cmdLongOption, or cmdShortOption
  # our first case switch because it dictates how we process the argument (since cmdArgument doesnt have a value)
  case kind
  # cmdArgument is without the "-" in the arguments, 
  # like nim c ./file.nim, the c is a cmdArgument
  of cmdArgument:
    # echo "Got arg with key: ", key
    discard #(should discard this iteration of the loop and move to the next one)

  # cmdLongOption, cmdShortOption: 
  of cmdLongOption, cmdShortOption:
    case key
    # -p is to specify port number as in -p=443 or -p:443 but not -p 443
    of "p":
      # echo "Got arg 'p' with value: ", value
      # change the port value string, to an int & store in portNum variable defined above
      discard parseInt(value, portNum, 0) 

  of cmdEnd:
    discard # this was the final iteration, so we discard this and move on to after the loop now