Type instability: 1-player game, symmetric 2-player game

[oyamad]

The problem causing #2 (comment):

• If an M-dimensional array is passed with M>=3, then NormalFormGame{T<:Real,M}(payoffs::Array{T,M}) is called, which returns a NormalFormGame with N=M-1>=2 players.

• If a 2-dimensitonal array (matrix) is passed, then NormalFormGame{T<:Real}(payoffs::Matrix{T}) is called and it returns

  • a 1-player NormalFormGame if the input array is n x 1;
  • a 2-player NormalFormGame if the input array is n x m with m>=2 and is square (n=m), in which case the game is thought of as a symmetric 2-player game.

The latter design is the source of the type instability.

My proposal is:

• let NormalFormGame{T<:Real}(payoffs::Matrix{T}) always return a 2-player NormalFormGame (if payoff is square), so that a 1-player game cannot be constructed by a payoff array (vector in this case) and must be constructed by NormalFormGame(player_with_no_opponent), where player_with_no_opponent is of type Player{1,T}.

[oyamad]

Alternative is #5, with removing NormalFormGame{T<:Real}(payoffs::Matrix{T}).

[sglyon]

I think I like your proposal in the comment at the end of the original post here.

But, I will totally defer to your judgement here.

[cc7768]

Hi @oyamad. I think this is a very sensible proposal and a nice solution to the problem.