String interpolation would be safer, as it would make the intent clearer, and you wouldn't risk bumping in corner cases. It would be even safer if the protocol could be overrided such that you wouldn't have to use Object#toString, but for Java that's too much already.
Java has been a very conservative language. And I understand why.
But it's funny how, for many features that were added later, people were rationalizing their absence with such lines too. E.g. we don't need anonymous functions / lambdas, as anonymous classes are enough. Well, turned out that Microsoft was right all along when they released those in J#.
Also adding a template engine is overkill for doing string concatenation.
There's nothing wrong with that. If string interpolation is really useful, then Java will add it some years down the line.
It's cheap to add features but literally impossible to remove them. There's no way to undo a mistake in language design. That's an asymmetry. I'd rather err on the side of caution than kitchen-sinking it.
I like how Java binaries still work on the latest Java, however, if distribution happens via binaries, why should the language keep source compatibility anyway?
Or, you know, the latest compiler could allow you to select the source code version you want. And automated code migration tools can work too.
---
Err'ing on the side of not getting features is why Java has lost a lot of mindshare.
Java is still super popular, but that's basically in spite of the language itself, because the language is awful.
Now is the year. String interpolation is really harmless feature.
echo "$(ls)"
in my zsh, so I'm not sure what to say, to be honest.
Are you saying that they haven't been around for long or that they failed? If latter, then I respectfully disagree. Any recent JS and Python code I have seen uses them extensively. They are also a joy to use, and imho improve readability immensely. Ergonomics matter. This is one aspect of Python3 I would miss the most if I had to go back to 2.
