On: Building on Rock, Not Sand

[agumonkey]

in the end the idea is that if you are semantic aware, then everything is safe; it's just operations from exp -> env -> store to env -> store etc etc

[nine_k → agumonkey]

Indeed! You can write safe programs for e.g. the original Turing Machine.

But I bet you'll end up writing tools to make creating a safe program of any non-trivial size feasible. A large class of these tools is usually called "programming languages".