What are the strengths and weaknesses comparing the two languages ?
I can name a strength of dlang is the working binding to tk and gtk.

On Wednesday, 28 April 2021 at 22:41:03 UTC, Alain De Vos wrote:

Crystal has no installer for Windows

On Thursday, 29 April 2021 at 05:41:45 UTC, Imperatorn wrote:

Is this a strength or a weakness? (SCNR)

On Wednesday, 28 April 2021 at 22:41:03 UTC, Alain De Vos wrote:

Crystal is Web-only focused.

And Crystal is not popular, even compared to D.

On Thursday, 29 April 2021 at 05:54:24 UTC, Berni44 wrote:

lol :)

In all seriousness though. Since it a quite large population of the world, it's a weakness.

On Wednesday, 28 April 2021 at 22:41:03 UTC, Alain De Vos wrote:

Less type annotations, fewer guarantees, less compile performance as cons.

What is the importance of type-annotations in which cases.
@X @Y @Z makes code sometimes unreadable.
Sometimes there is a good reason

On Thursday, 29 April 2021 at 22:47:08 UTC, Alain De Vos wrote:

Specifying invariants which becomes very important when refactoring code.
Further it aids as documentation to understand the structures behind.

You mean something like List!(HashMap!(String,T)), yes, but I like it in productive code.
It's often the case that verbosity becomes a plus in productive software development, as more people have to read code that to write it, a reason why Java is so successful

Mostly for prototyping and obvious cases. But the most important point of that is to write faster, I wish the IDE would help for this instead of the compiler's inference.

I even think D doesn't even profit very well for inferred types, you need anyway to specify auto which only saves work for large type(application)s.
But when they are large, you probably want to prefer annotating the type for the variable.

Instead, I want to point to some interesting solution C# offers to save typing and also being explicit about the type:
https://devblogs.microsoft.com/dotnet/welcome-to-c-9-0/#target-typed-new-expressions

In fact, one could imagine that they overload the new operator (at compiler level) to infer the type from the call site type annotation.

On Wednesday, 28 April 2021 at 22:41:03 UTC, Alain De Vos wrote:

Pros of Crystal

1. Attractive syntax. I like Ruby like syntax. It's really expressive.

Cons of Crystal

1. It doesn't have a compiler for Windows. It uses WSL based compiler and I think it's a bad idea.

I don't think I need to tell the pros & cons of D lang in it's own forum.
BTW, I wonder to see someone says that they have succeeded in compiling a tkD example code. I tried it with no luck. So I gave up that idea.

tkd works perfectly. Which O.S. are you using ? I can guide.