Nim Nuggets: Nim talk at Strange Loop 2021

[Walter Bright]

On 10/17/2021 3:03 AM, Ola Fosheim Grøstad wrote:
> On Sunday, 17 October 2021 at 08:20:24 UTC, Imperatorn wrote:
>> And still, in 2021 using C++20, compile time features are severely crippled.
> 
> How so? Anyway, what Walter said was not accurate. Languages are usually defined 
> in a way where compile-time optimizations are optional and an implementation 
> detail. Compile time evaluation of functions is nothing new, and a common 
> optimization.

You're confusing data flow analysis and function inlining with ctfe. I know how 
data flow optimizers work, I was the first to implement one for DOS compilers in 
the 80s.

C and C++ compilers have enjoyed the best optimizers in the industry for 
decades. But not one of them could compile:

   int square(int x) { return x * x; }

   const int s = square(2);

Being able to do such NEVER occurred to anyone in the business. It's one of 
those ridiculously obvious things that nobody thought of for decades. It's so 
obvious people today cannot even conceive of not thinking of it.

I developed compilers with optimizers for 20 years before it occurred to me. 
Implementing it around 2007, it was like a bomb went off in the D community. 
(Don Clugston was the first to recognize what it could do.) From there it spread 
to C++ and pretty much every other compiled language.