Style Guide: AVOID bracketed interpolation of simple identifiers.

[seaneagan]

If it's in the linter:

https://github.com/dart-lang/dart_lint/issues/3

seems like it should then also be in the style guide:

AVOID bracketed interpolation of simple identifiers.

bad

print("Hi, ${name}!");

good

"Hi, $name!"

[seaneagan]

Should also mention that it's OK when followed by alpha numerics:

good

print('\$${dollars}USD');

[pq]

I'll leave to other's on the style council to deem whether this is style guide worthy (ahem @munificent) but I should chime in on this point:

If it's in the linter ... seems like it should then also be in the style guide

I would turn it around actually:

if it's in the style guide it should be in the linter

My thinking is that the linter will certainly provide rules that transcend the guide. Indeed it may even have rules that contradict it (or certainly rules that are mutually incompatible with each other). Having said that, there should certainly be a Rule SET provided by the linter that is complete agreement with the guide.

[munificent]

👍 for having this in the style guide. I would say:

AVOID using braces in interpolation when not needed. If you're just interpolating a simple identifier, and it's not immediately followed by more alphanumeric text, the {} can and should be omitted.

[pq]

Awesome. Where do we go from here? Does @kwalrath own changes or is a pull request welcome?

[kwalrath]

Either one is fine, but I can take care of this one.

[pq]

👍 Thanks @kwalrath!

[kwalrath]

https://chromiumcodereview.appspot.com/913733003/

[munificent]

Thanks!