[flavio81]

>What makes this particularly suspicious is the fact that, in the past, Lisp programmers have claimed to recover the advantages of other statically typed languages in a Lisp setting, but there have always been huge caveats, like “the system can be very easily circumvented, reducing the benefits of static typing to nothing”

Common Lisp programmers use static typing for gaining speed, not for any kind of added "safety". For safety we have very good package isolation, really strict typing, typecasing, multimethods, conditions and restarts, and the friendly runtime overseeing the code execution like a god and helping the programmer as a good loyal friend would do.

[catnaroek]

> typecasing, multimethods

These features exist for expressiveness, not safety reasons. Although it must be noted that these features make it hard to verify the correctness of programs in a modular fashion. Typecasing makes language-enforced abstraction essentially impossible.

> conditions and restarts

These features exist for debuggability, not safety reasons. Safety means ruling out delimited classes of “bad” behaviors by (language) design.

> friendly runtime overseeing the code execution

Now this is a safety feature, but it is only kind of incompatible with the zero-overhead needs of a low-level language.