Except in dynamic languages most people reinvent the wheel and don't quite get to a monadic interface. Like Javascript promises. They could have had ONE interfa

Except in dynamic languages most people reinvent the wheel and don't quite get to a monadic interface. Like Javascript promises. They could have had ONE interface that is consistent. But Promises are actually a special snowflake that solves the problem in a slightly different way with a slightly different interface. And that's because nobody can complain that their stuff doesn't compile due to it not satisfying some interface.