linked list - Handling player on turn with Objective C -

i'm creating simple app has list of characters , list of (4) players, players reference playable character.

i'm stuck on how following:

1. make reference current player on turn
2. find out next player on turn is
3. handling last player return first player on turn.

ideally, able after, first, last before commands on nsmutablearray, of these i'm able lastobject, there no firstobject, afterobject, etc.

i believe can fake before,after,first commands objectatindex; ideally not want rely on numeric references because incorrect -- if mutable, size change.

typically, able following in pseudocode.

global player_on_turn.player = null //player_on_turn pointer player object  ; handle next player on turn if (player_on_turn.player = null) error("no player on turn assigned") if (sizeof[playerlist]==0) error("there no players in game") if after player_on_turn = null   ; reset   player_on_turn.player = first player else   ; move next player on turn   player_on_turn.player = after player_on_turn.player end if 

with in mind, best strategy handle player on turn concept described in 1-2-3 example above.

thanks

it doesn’t matter data structure you’re using - @ level have rely on numerical index (except if using linked lists). , alright. if don’t want use in main game implementation alright, too. create class encapsulates things. first think of operations need support. guess here those:

- (playerobject *) currentplayer; - (void) startnextturn; 

if have can write game using primitives , worry how best implement later. can change @ time without breaking actual game.

my recommendation this:

- (playerobject *) currentplayer; {      return [players objectatindex: currentplayerindex];  }  - (void) startnextturn; {     ++currentplayerindex;     if (currentplayerindex >= [players count]) {          currentplayerindex = 0;     }  } 

using index there ok, if array mutable. if have methods change player array can take care of necessary changes currentplayerindex.

having object makes easy write unit tests. global variable suggest in pseudo-code makes impossible write meaningful unit tests.