[mnarayan01]

  if a = foo()

versus:

  if (a = foo())

Sometimes idiomatic patterns vary based on things which are not amiable to mechanical correction.

[quxbar]

The trick is to ban even the correct but (to a human) ambiguous patterns. In this case, I wouldn't let you do assignment on the same line as the conditional.

[squiggleblaz]

With an `if` it's probably superfluous and therefore bannable without cost, but sometimes it can make a `while` loop so much more concise - since the alternative would be to write the same code before the loop and at the bottom of the loop. It is the cost of inexpressive languages.

[fipple]

In what language do those produce different results?

[mattnewton]

In many people’s head-parser, the first one looks like an equality check (but is in fact assignment). The parens try to clue people into “this is an assignment expression!” I think, but personally I wouldn’t allow an assignment expression in an if statement even with parens.

[munchbunny]

While you have a point, I don't think the exception should disprove the rule. Even if a few specific style patterns can't be automated, the bulk can be and it's probably better to have them enforced at the pre-compile stage.