That would be nice if devs always wrote code sequentially, i.e. left to right, one character at a time, one line at a time. But the reality is that we often jump around, filling in some things while leaving other things unfinished until we get back to them. Sometimes I'll write code that operates on a variable, then a minute later go back and declare that variable (perhaps assigning it a test value).
If i decide to add a new field to some class, i won't necessarily go to the class definition first, I'll probably write the code using that field because that's where the IDE was when i got the idea.
If I want to enhance some condition checking, i'll go through a phase where the piece of code isn't valid while I'm rearranging ifs and elses.
Often, not even then.
But some languages just won't let you do that, because they put in errors for missing returns or unused variables.
BABLR takes Hazel's idea and takes it about 18 steps further, potentially making embedding gaps a feature of every editor and programming language.
As long as solutions don't have a way to scale economically they'll be academic, but BABLR makes this not academic anymore.
Gaps are present in the embedded code representation, e.g. if · is a gap we would represent the result of parsing `console.log(·)` using a "gap tag" (written `<//>`) in a CSTML document that will look like this: https://gist.github.com/conartist6/75dc969b685bbf69c9fa9800c...
But you could have a compiled language where errors were limited to the function when possible, like by emitting asserts.
Syntactically invalid.
I hope someone makes a fork that lets you disable those silly errors in debug mode
Forking a large and very active project like this is a mug's game.
Reading through the article, the author makes the argument for the philosophy of progressive disclosure. The last paragraph brings it together and it's a reasonable take:
> When you’ve typed text, the program is valid. When you’ve typed text.split(" "), the program is valid. When you’ve typed text.split(" ").map(word => word.length), the program is valid. Since the program is valid as you build it up, your editor is able to help you out. If you had a REPL, you could even see the result as you type your program out.
In the age of CoPilot and agent coders I'm not so sure how important the ergonomics still are, though I dare say coding an LSP would certainly make one happy with the argument.