Have you heard about Racket's custodians? [1] http://docs.racket-lang.org/reference/eval-model.html#(part._custodian-model) http://docs.racket-lang.org/referenc

Have you heard about Racket's custodians? [1] http://docs.racket-lang.org/reference/eval-model.html#(part._custodian-model) http://docs.racket-lang.org/reference/eval-model.html#(part....