"no variable or argument declarations are necessary."

[Istvan Albert]

> What can one do to swiftly detect this type of bug?

While I can only speak from my own experience I can't  remember a
single instance where this type of bug caused any kind of serious
problem.  IMHO these are very trivial errors, that get caught
immediately and I would not  even qualify them as bugs, more like
typos, spelling mistakes, etc.

Real bugs are a lot more insidious than that, and they might even occur
more frequently  if there was type checking ...  since it might even
lead to longer code

just my $0.01

Istvan.