Tagir Valeev

@tagir_valeev@mastodon.online
739 Followers
53 Following
883 Posts
AboutWork at JetBrains. Java Champion. Check my Java book: https://mng.bz/671p
Twitterhttps://twitter.com/tagir_valeev
LinkedInhttps://linkedin.com/in/tagir-valeev
Tagir ValeevJun 2
Sharat ChanderMay 29

#Java peers...the 2025 @intellij IDEA Conference is around the corner (June 3-4)! There's still time to register for this FREE virtual event: https://lp.jetbrains.com/intellij-idea-conf-2025/

Hear from host @maritvandijk and me as we kick things off to celebrate 30 YEARS OF JAVA!

IntelliJ IDEA Conf 2025 | June 3-4, 2025

We invite you to join us for IntelliJ IDEA Conf 2025 and gain insights from industry leaders and experts.

JetBrains: Developer Tools for Professionals and Teams
Tagir ValeevJun 2
Cay HorstmannJun 1

Puzzler of the week (inspired by @tagir_valeev)

How many of the following have value "%"?

"%%".formatted()
"%1%".formatted()
"%-1%".formatted()
"%1$1%.formatted()

One
22.2%
Two
22.2%
Three
22.2%
All four
33.3%
Poll ended at .
Tagir ValeevMay 26
TIL: In #Java format strings, you can specify indentation to a single percent character.
Tagir ValeevMay 23
Kinda cool #Java30Years #JetBrains https://www.youtube.com/watch?v=kHybgBHqL2A
30 Years of Java

YouTube
Tagir ValeevMay 22
Here's how the analytics for a single flaky test looks like inside the IntelliJ project.
Show threadTagir ValeevApr 15
And it prints 'From var'. However, you can remove the variable declaration, and it will resolve to a class and print 'From class'. There's no ambiguity, as an instance-bound method reference has a priority over a statically bound one.
Show threadTagir ValeevApr 15

You can try something simpler, e.g.

void main() {
class C {
static void run() {
System.out.println("From class");
}
}
Runnable C = () -> System.out.println("From var");

Runnable r = C::run;

r​.run();
}

IDE resolves C properly to a variable.

Show threadTagir ValeevApr 15
One of the few places where both class name and variable name can appear is the method reference qualifier. In this case, first it's assumed to be an expression (variable reference), and if it doesn't work, then there's an attempt to resolve a class. If the variable works, we don't try a class.
Show threadTagir ValeevApr 15
The correct answer is counter-intuitively, Outer2​.foo. Normally, classes and variables have separate namespaces in Java, so importing class and importing variable (static field) with the same name does not produce an ambiguous import.
Tagir ValeevApr 15

Ok, here's my solution. Full of warnings, of course, but who cares about warnings?

void main() {
O<O<O>> O = O<O>::<O>O;
}

interface O<T> {
void use(O c);

default <C> void O() {
}
}
https://mastodon.online/@tagir_valeev/114335110570765456

Tagir Valeev (@tagir_valeev@mastodon.online)

Provide the declaration of the O type, so this statement could be a valid #Java statement: O<O<O>> O = O<O>::<O>O;

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