'REPL is opening interactive mode (if the language supports it) and entering "2+2".'

If I'm going to enter "(+ 2 2)" using my normal development tools, I'm probably going to start Emacs and tell it to start a SLIME session with one of the Common Lisps I use. When I do that, it'll create a repl buffer, because that's the way I have slime configured.

I mean, I don't have to load slime-repl. I could just interact with the Lisp's read, eval, and print functions directly from an arbitrary buffer without involving the SLIME repl display at all. But, y'know, force of habit. Also, I do occasionally type something in SLIME's repl buffer, especially if I want to see some big wad of output and don't want it spewed into the middle of the expressions I'm working with.

Most likely I won't type "(+ 2 2)" in the slime-repl buffer, though. I'm more likely to type it into a scratch buffer and send it to the Lisp by hitting C-x C-e. As soon as I start typing Lisp code, I know I'm probably going to want to add some more and maybe edit it and probably send it to the Lisp again. That's just more convenient if I have it sitting in a buffer in front of me, and not scrolling off the top of the repl buffer into infinity.

So am I working in a repl? Lisp is running a loop waiting for input. I'm sending expressions to it. It's reading them, evaluating the s-expressions produced by READ, and then printing the resulting values to a stream I can look at. Sounds like a repl to me. It's what I've always understood a repl to mean, including when I'm building them.

Does it count as working in a repl when I use a keystroke to send "(+ 2 2)" to the Lisp from the scratch buffer, or does it only count if I actually physically type the text in the buffer where the Lisp displays its prompt? What if there is no prompt? What if I start Lisp and SLIME but don't load the slime-repl extension? Does that mean that the loop that is reading, evaluating, and printing stops being a repl?

I'll probably save my scratch buffer to a file at some point, if there starts to be enough text in it that I think I might forget some of it. Does it stop being an interaction with the repl the instant I save the buffer to a file? I can save the slime-repl buffer to a file, too; does it stop being a repl when I do?

What about Lisp and Smalltalk environments where the read-eval-print loop doesn't display a prompt? Take a Smalltalk or INTERLISP worksheet, for example. Is it a repl if there's a loop reading, evaluating, and printing expressions, but no prompt? Does it stop being a repl if the incremental inputs and outputs get saved to a file? Does it count if it's not a text file, but the environment automatically saves the state of the worksheet to an image file that it automatically deserializes the next time you start the environment?

I don't think I'll adopt your lexicon, but I am sort of curious where its boundaries are.

> If your code is in a file, and you're running the code from the file, that's not REPL. that's interpreting or compiling a file.

It is not “interpreting or compiling a file” if the tool you are using to evaluate code in the file is sending isolated blocks of code to a REPL and not, well, interpreting or compiling the file.

> REPL is opening interactive mode (if the language supports it) and entering "2+2".

No, a Read-Eval-Print Loop (REPL) is not exclusively used by a user typing keystrokes at a terminal; like other terminal software, it is a candidate for being driven by other programs.

> You calling anything else REPL is just wrong, misleading and confusing.

You insisting a REPL isn't a REPL when the “Read” part is reading something other than keystrokes directly entered by a human user is just wrong, ignorant, and confused.

I think most Lispers reckon REPL development the way it was described; analogous to editing code in a Smalltalk Browser and Doing/Inspecting it in a Smalltalk Workspace. WRT Smalltalk, you can Do/Inspect code in a Workspace and then create a class and copy it over but this typically isn't done that much.