Reading IDX Files in D, an introduction to compile time programming

[Carl Sturtivant]

On Saturday, 22 August 2020 at 07:04:19 UTC, Petar Kirov 
[ZombineDev] wrote:
>
> I feel like limiting CTFE just gives a false sense of security 
> and destroys many interesting use cases. If a part of my build 
> system will do directory traversal to build the list of files 
> to import, what difference would it make to not have this as a 
> single build step. The argument that somehow
>
>     dmd -run gen_code.d | dmd -
>
> Is more secure than just:
>
>     dmd file.d # file.d is allowed to access the FS at CT
>
> makes no sense to me.
>
> See Jai for example. You can run absolutely *any* code at 
> compile time. 5 years ago Jai's creator made a demo of running 
> an OpenGL game at CT [1]. In the same demo he also used CTFE to 
> validate calls to printf. He made the case that while many 
> compilers go the route of hard-coding checks for printf style 
> functions in the compiler, he thinks that users should be able 
> to implement arbitrary checks in their code. And 5 years later, 
> instead of D expanding the frontiers of what's possible via 
> CTFE, printf checking was hard coded in the compiler [2].
>
> [1]: https://www.youtube.com/watch?v=UTqZNujQOlA
> [2]: https://github.com/dlang/dmd/pull/10812/files
>
> I don't need say that unlimited CTFE has been a huge success 
> for Jai. What I wish is that we can learn from this stop 
> bringing arguments that C people would bring for D's CTFE ("My 
> Makefile calls a Python script to generate C code and it's 
> doing just fine, so I don't think one should be allowed to run 
> code at compile time, as it will make the code just harder to 
> follow").
>
> As another example, types in Zig are first class citizens [3] 
> and can be manipulated with CTFE just like any other value. 
> "Type functions" in D should just be regular D functions taking 
> types as parameters and returning types.
>
> [3]: 
> https://ziglang.org/documentation/master/#Introducing-the-Compile-Time-Concept

Strongly Agreed!