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Javascript has automatic semicolon insertion. This function:

  function a() {
    return
      true;
  }

return undefined.

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This Python

    def a():
        return
        False;

returns None.

That's because in Python the line break is the statement terminator.

Python and JavaScript both accept semicolons or line breaks to terminate statements. JavaScript's syntax problems are a bit more subtle than just that.

Same in ruby

    def foo
     return
     true
    end

returns "nil"

I don't like referring to this as "automatic semicolon insertion". The behavior you're referring to here is really about line termination/continuation.

  var a =
  42

is only parseable one way because assignment requires an argument.

Javascript just happens to make assumptions with certain kinds of ambiguities, but then, all programming languages do.

Actually that is the name that appears in the ECMAScript official language specification:

http://bclary.com/2004/11/07/#a-7.9.1

that just makes me a bit depressed then :)

Thanks for the reference. I still think this is a general issue, and calling it semicolon insertion confuses the issue :\

Well, it is the combination of semicolon-insertion and restricted productions.

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