Cleaning out the clutter

Kotlin future features survey results: What to keep and what to toss

Gabriela Motroc

© Shutterstock / Grasko

The results of the Kotlin future features survey are here. Respondents were asked to nominate three most expected features, as well as one feature that they would like to be banned (optional). Let’s see what Kotlin users want to keep or ditch.

JetBrains offered Kotlin users to make an impact on the future of this programming language — the Future Features Survey ran in April and received roughly 850 replies. Respondents were asked to nominate three most expected features, as well as one feature that they would like to be banned (optional). According to the blog post announcing the results, most people used up all three slots for positive feature nomination and 300+chose to skip the negative nomination.

Kotlin Future Features Survey, April 2017, Anonymized Data

You can see the list of proposed features here.

SEE ALSO: The sprint to the top: Kotlin plays in the big leagues now, TIOBE index shows

Kotlin features: Nominations for and against

Kotlin users have chosen their favorite features: “Collection literals”, “SAM conversions for Kotlin interfaces” and “Truly immutable data”.

Andrey Breslav, lead language designer of Kotlin at JetBrains noticed that the most controversial feature seems to be  “Private members accessible from tests” with 108 votes for and 120 against. He explained that the result is not that shocking since “designing for testability is widely recognized as a good practice.”

However, he was a bit puzzled over the “Overloadable operators | and &” controversy (46 votes for and 50 against) and asked respondents to share their motivation in the blog post’s comments section.

SEE ALSO: How well do you know your Kotlin trivia?

And the negative nominations are …

The results may be difficult to interpret because “Optional commas” and “Optional trailing commas” have been put under the same feature. Breslav also apologized for forgetting to include “Ternary conditional operator” in the survey and promised to look into this feature.

Discrepancy alert!

Breslav noticed that the results of the survey conducted at the Kotlin 1.1 Launch Event turned out quite differently. He believes that “the results may have been affected by the fact that people saw previous votes and got biased, but it’s hard to be sure. Other factors may also be relevant, e.g. the audience at the meetups may be a bit different from the online survey audience.”

Kotlin future features: Top of the class

What do Kotlin users expect from this programming languages? These features are the clear leaders:

  • Collection literals
  • SAM conversions for Kotlin interfaces
  • Truly immutable data

As Breslav pointed out, the rest of the features received significantly fewer nominations. “Truly immutable data is very desirable indeed, but really tough too, so no promises there. The other two seem tractable in the foreseeable future, and multi-catch looks like a good thing to look into as well.”

He warned that JetBrains is not committing to implementing any of the features presented in the survey in a certain time frame or at all. Although they care about users’ needs, they refrain from promising anything upfront.

But don’t despair, there’s still hope. “For one thing, there’s significant design work required before we even know if these features can be fit pragmatically (and elegantly) into the language,” Breslav concluded.


Gabriela Motroc
Gabriela Motroc was editor of and JAX Magazine. Before working at Software & Support Media Group, she studied International Communication Management at the Hague University of Applied Sciences.

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