newCTFE Status September 2019

[rjframe]

On Thu, 05 Sep 2019 10:55:30 +0000, Dominikus Dittes Scherkl wrote:

> On Thursday, 5 September 2019 at 10:23:18 UTC, Stefan Koch wrote:
>> Well no, if you have CTFE code up the stack which catches the Exception
>> then it's fine.
>> It's only a problem if the Exception would escape out of the
>> ctfe-entry-point.
>>
>> Therefore I do have to provide the means for Exceptions to be thrown
>> and caught within ctfe.
> 
> OMG. Do we really want a program to compile that throws and catches
> exceptions _during compilation_? Who programs such crappy shit should
> suffer worse than a simple compile error!

If `a` calls `b` calls `c` at compile-time, `c` can throw something that 
`a` can catch, interpret, and rethrow with a more meaningful message/
context.

I'd argue that it is bad practice to have a thrown Exception at CT that 
doesn't result in a failed compilation; compile-time exceptions should be 
treated by the programmer like failed assertions - something has gone 
wrong that needs to be fixed before deployment.

It is possible though:

---
int fail() { throw new Exception("error"); }

int func() {
    try {
        return fail();
    } catch (Exception) {}
    return 0;
}

enum a = func();
void main() {}
---


--Ryan