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When linting dart files, one of the checks that seems relatively standard (and part of the google pedantic style) is unnecessary_this, which favors not using the explicit this keyword unless necessary when the instance variable is shadowed.

Coming from more of a Java/Python background, where (in Java) the standard seems to favor explicit use of this., plus a pretty typical checkstyle check RequireThis, I'm wondering the rationale behind dart's preference for this type of style check - to me it seems Java and Dart have similar semantics for implicit this's, so why are the standard preferences opposing each other?

In the unnecessary_this docs, it says:

From the style guide:

DON'T use this when not needed to avoid shadowing

However the linked style guide does not mention it or provide any rationale.

I'm wondering because I'd like to have a check that is the exact opposite of unnecessary_this, but there doesn't seem to be one so I'm curious if there's something about dart I don't know that is rationale for implicit this.

tplusk
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    There's nothing special about the language itself. But it seems that most Dart programmers seem to prefer unnecessary verbosity (and thus also prefer using `var` with type-inference over explicitly declaring variable types and `import`s without explicit prefixes). – jamesdlin Apr 19 '20 at 18:46

1 Answers1

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Dart's style-guide focuses a lot on "don't write what is not necessary", and unnecessary_this is one of its representations

The overall rationale behind it is that by removing the obvious redundant bit, this decrease visual noise, and therefore increase readability (while also being easier to type).

The only reason I can think of for wanting a "require this" lint is to avoid getting confused by variable shadowing. But then, might as well have a lint for "don't shadow variables".

Rémi Rousselet
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