Mix pineapple juice, lemon juice, salt, flour, butter, egg yolks(mix these in while mixture still cool or you will end up with scrambled eggs),and sugar together in a small sauce pan. Cook over low heat until thick.(Not quite pudding thick)Stir constantely
Cool mixture in refridgerator until completely cool stirring occasionally. Then mix in 1 container of cool whip. While mixture cools cut up fruit.
Pour mixture over fruit and nuts and refridgerate until ready to serve.