Did you see the other code examples that came up in that twitter
conversations?
For example:
This worrying little program compiles:
func f() -> Int {
return a
}
let a = f()
It also compiles if you print(a) at the end, and it will print 0.
If we replace Int with [Int] it will still compile but crash when run.
And also this:
AnotherFile.swift containing:
func f() -> Int {
return a
}
let a = f()
main.swift containing
print(a)
Compile, run (for eternity, at 0% CPU).
/Jens
···
On Thu, Sep 22, 2016 at 3:13 AM, Joe Groff <jgroff@apple.com> wrote:
> On Sep 21, 2016, at 2:22 PM, Jens Persson via swift-users < > swift-users@swift.org> wrote:
>
> // This little Swift program compiles (and runs) fine:
>
> func foo() -> Int { return a }
> let a = 1
> let b = 2
> print(foo())
>
> But if `foo()` returns `b` instead of `a`, I get this compile time error:
> "Use of unresolved identifier `b`"This looks like a bug to me (cc-ing Jordan, who's thought about global
scoping issues more than me). In "script mode", it shouldn't be possible to
refer to a variable before its initialization is executed. However, the way
this is currently modeled is…problematic, to say the least, among other
reasons because script globals are still visible to "library" files in the
same module.-Joe