A REPL or read eval print loop is what we called an interactive prompt back in the day when I learnt Python and Ruby.
He goes on to say:
For a REPL to make sense you need to be able to test small chunks of code. Like this function or this expression; or my typical thing, “would this work” or how the fuck was that syntax again?
I’ve sometimes found that they have a downside. When you are looking for code examples, then if a language has a REPL, very often the examples show the use of a feature in the REPL. Which may be fine, but is not so helpful if you’re trying to find out how to construct a class or a function.
Which point, to be fair, Hjertnes does address:
In other words, if your language require a lot of “foreplay” to run code, like declaring a namespace and a class etc (I’m looking at you Java and C#) it will probably not be the right thing. But if you can evaluate code without much fuss it is.
Java is supposed to be getting one soon, I believe, if it’s not already in version 9.