The new print() is Flipping Busted (nope, it’s me!)

owensd

UPDATE Friday, June26th @ 10:49 PM

Yep… so I've tracked down the issue: http://www.openradar.me/21577729. The problem is that single parameter, generic functions are implicitly turning multiple parameters into a tuple. That's the root cause of the initial bug report.

Good times.

Here's the code if you want to try it out:

func f<T>(value: T) {
    print("value: \(value)")
}

func f<T>(value: T, hi: Int) {
    print("value: \(value) \(hi)")
}

f("hi")
f("hi", append: false)
f("hi", append: false, omg: "what?")

f("hi", hi: 12)  // calls f(value: T, hi: Int)
f("hi", Hi: 12)  // calls f(value: T)

UPDATE Friday, June 26th @ 10:02 PM

OK… so I totally screwed up… It's my fault, Swift is just fine (kind-of). (I still want print() and println() back though).

SO… it turns out I have a typo in my code below in my bug report rant… 

for  _ in 0 ..< titleWidth { print("━", appendNewLine: false) }
print("‚ïá", appendNewLine: false)

Should have been this…

for  _ in 0 ..< titleWidth { print("━", appendNewline: false) }
print("‚ïá", appendNewline: false)

I'll let you spot the difference. I am unsure as to why I did not get a compiler error. The only reason I noticed the issue is because I tried to workaround the issue reported below by using another overload of print(). That overload did correctly flag my labeling error. So, still a bug with print(), but no where near as bad as I originally though below.

Also, in the playground, print("hi", whateverIWant: false) works…

Anyhow, back to your regularly scheduled broadcast…

SHAME POST FOR ALL TO LEARN FROM…

I'm just going to copy my bug report here as I think this is worthy of being shared more broadly…

Bug Report First of all, I'm sure this bug has been logged before, but I don't care because this is so flipping irritating right now.

A "systems language" that has no proper ability to write console apps and output text to the screen succinctly is just broken. The move to replace print() and println() with a single function print() with an overload – terrible decision.

Ok… breathe… I can deal, it's just an overloaded function now, no problem…

Imagine your surprise when you try and use it to print out some table headers:

for  _ in 0 ..< titleWidth { print("━", appendNewLine: false) }
print("‚ïá", appendNewLine: false)

And you get output like this in the console:

("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("━", false)
("‚ïá", false)

This is retarded and completely broken. Please change print() back to the proper print() and println() versions and fix the implementation to actually output correctly to the screen.

The new print() is Flipping Busted (nope, it’s me!)