[CyberShadow]

Correct. The language is designed to allow code written in it to compile quickly, and the reference implementation is very fast (both the front-end, and back-end). Small, script-size programs compile quickly.

However, D's compile-time metaprogramming facilities allowed us to get ambitious in some places... for instance, std.uni precomputes some Unicode lookup tables during compilation, and std.regex makes heavy use of metaprogramming to compile regular expression strings to D code, again during compilation. As a result, making use of those features will result in heavier load on the compiler.

[Asooka]

I don't like code that generates stuff at compile time precisely for this reason - I would much rather use some template language to pre-generate the source (I've even seen php used) and then compile it quickly. Of course that then needs support from the build system to correctly invoke the generator when the templates change and you run the risk of some developer changing the generated source instead of the template and wreaking havoc. I would very much like to have my cake and eat it - powerful code generation facilities in the language itself, but with a compiler that's as smart as the build system and can cache these for reuse when recompiling the same file. That would also allow easy integration with IDEs. For now, I've decided that the better balance is generating code using an external generator, checking everything in source control and requiring responsible people to do code review. YMMV of course, depending on what you're compiling and who you're working with.

[qznc]

I agree with you. It feels natural for lexer/parser generators for example (Yacc, Bison, AntLR, etc). Also for FFI bindings.

On the other hand, for the little things it would be weird. Would you do that for a single regular expression?