IMHO a REPL is table stakes in some of the domains in which nim is competing with other languages that provide it. REPLs have their faults, but a lot of people, particularly engineers that need to program to get their job done but aren't computer scientists, are used to these REPL-based workflows (which have a lot of advantages in some areas) and expect to be able to use them, otherwise they are just not interested (I'm thinking of people who currently use Matlab or python for data analysis or simulation, for example).
Beyond that, a proper nim REPL would be awesome in multiple contexts: * When learning nim. * When exploring a problem domain that you don't master yet. * When debugging (e.g. imagine being able to make plots or print the content of your variables like you can do by adding a call to "breakpoint()" to one of your python scripts).
