Can a programming language be written that makes it impossible to write invalid code and be expressive?

[Ola Fosheim Grøstad]

On Sunday, 28 July 2019 at 07:30:02 UTC, Ola Fosheim Grøstad 
wrote:
>
> Anyway, the key point of the halting problem is that this 
> situation cannot be avoided unless you restrict the space of 
> problems that can be solved.

Of course, in theory it is still possible since we always can put 
an upper limit on the amount of memory, time, input.

But it is not something we can expect to be resolved in our 
lifetime.