I know this is hardly the first post about scoping being “different” in different places (documented here ), but I had a thought and couldn’t really find any post that addressed it. I’ll try to give a short recap: version 1 tried to simplify things by going full hard scope, and it’s pretty compellin…

I think one of the reasons is that there is no much difference between a variable that addresses a function and any other variable that addresses a value, or vector. Therefore, with that hard scope one would need to declare even all the functions which are being used inside each other function. Of c…

[image] PSA: Julia is not at that stage of development anymore Internals & Design You heard about this brand new exciting programming language called Julia and have some suggestions for how it should work. Wonderful! We’re happy to have you here and help you learn the lang…

I am aware that version 1 commits to stability, so I’m not expecting a such a fundamental (and featureless) syntax change to happen in future versions. I meant this question more in past tense: the even-harder scope seems to me like an obvious idea someone would have thought of already (the outer ke…

[image] Benny: the one hassle is a very explicit line in the block like outer x, y, z naming all the outer local/global variables to check for. Seems super annoying, no?

Personally, writing that extra first line would be a minor hassle to me because it feels similar to listing variables in a method/struct definition, and it would save me some time checking which variables came from outside the block. I do this much with a comment, though. EDIT: actually seems like …

You’re right, needing to write outer println over and over would legitimately be annoying. This could be mitigated by not requiring outer for calls println("hello") or const variables, but that doesn’t cover outer variables like x = println.

Functions and const variables appear to be already treated differently, so I am not really sure if that is a reason for that final behavior. I wander if it would be possible to create a macro like @global_warn f().. which would throw an error, or warning, if any non-constant global is used inside th…

[image] Benny: EDIT: actually seems like a huge hassle now that it’s been pointed out that method names are (const) variables One lesson from all those scope discussions is that scoping rules have complex interactions with each other and the rest of the language, so gotchas like this are comm…

Now that it’s clear it’s too much of a hassle to declare outer to use any outer variable (it would even include methods), I’m thinking what if outer was required to reassign an outer variable. Basically every variable in a scope that is assigned a value is treated as if it was declared local by defa…

I’ve considered that design before—in which case you really want the boundary where an outer is required to be function (and probably let), since requiring outer to assign to a local from a loop would be very confusing and irritating. The biggest issue with this approach is that it makes closures be…

There is an alternate design suggested by this: do-blocks, instead of being simple syntactic sugar for closures, could become something a bit different—you could make the rule that outer is required to assign to an outer local only in a closure that is syntactically declared with one of the function…

Why not an even-harder scope?

Internals & Design

Tamas_Papp November 13, 2020, 12:03pm 2

Topic		Replies	Views
Toward a real and final solution to Julia’s variable scope issue Internals & Design	37	2543	June 8, 2023
Global scope confusion again General Usage question , scope	52	6961	May 17, 2025
Explain scoping confusion to a programming beginner New to Julia question	26	3353	August 11, 2020
Remove the soft scope altogether and make it global Internals & Design proposal , scope	49	4675	May 17, 2025
Another possible solution to the global scope debacle Internals & Design	231	19943	November 6, 2018

Why not an even-harder scope?

Related topics