[andrewzah]

What semantics is crystal lacking? Obviously it's not a 1:1 replacement as the ecosystem is different, gem management (shards) is different, etc. Crystal also has union types and concurrency.

For people who want a syntax like ruby + performance/concurrency, but are willing to deal with a different ecosystem and having to do more stuff by hand, Crystal is a nice choice.

[chrisseaton]

Local variables, method calls, basics like that are basically entirely different. Take the Ruby specification test suite and try to run it on Crystal, even with adding typing and other minor changes, and see how far you get.

(Ruby also has full concurrency, by the way.)

[sethrin]

Your criticism does not seem rigorously considered. Toy programs can often simply be renamed from .rb to .cr and be compiled and run as Crystal code. Crystal is not, however, trying to be a drop-in replacement: among other things, an enforced type system is not a minor change. Compilation is not a minor change to a language either. It's valid to say that you don't like the tradeoffs (and of course ideally you would have a full understanding of what those are), but it's incorrect to suggest that these languages are not extremely similar.

[andrewzah]

Crystal has local variables. I didn't mean to imply that ruby & crystal are 1:1 drop-in replacements, but there are a great many similarities. Enough for me as a ruby/rails dev to start on crystal projects with relatively little issue once I learned a bit about the standard library and the ecosystem.

Ruby's way of handling types is abhorrent compared to Crystal, though. Sorbet/RBS are unfortunate systems tacked on after people realized that type systems are actually really good and not really that verbose.

[dragonwriter]

> Crystal also has union types and concurrency.

Ruby has had concurrency forever, and as of 3.x also parallelism via Ractors.

[metadat]

You may be missing the point - Vanilla Ruby is relatively slow and expensive to scale.

That's why I use node.js *grin* /s