Ruby Tuesday, 20180925

Overview

Have a syntax similar to Ruby (but compatibility with it is not a goal).

• First Impressions
• Method Overloading
• Block Shorthand
• Structs
• Enums
• Tuples
• Abstract Classes

Be statically type-checked, but without having to specify the type of variables or method arguments.

• Type Restrictions
• Type Inference

Be able to call C code by writing bindings to it in Crystal.

• C Extensions

Have compile-time evaluation and generation of code, to avoid boilerplate code.

• Macros
• Macro Hooks

Crystal uses green threads, called fibers, to achieve concurrency. Fibers communicate with each other using channels, as in Go.

• Concurrency

Compile to efficient native code (based on LLVM)

$ crystal build 12-c-extensions.cr -o test  --cross-compile --target "x86_64-unknown-linux-gnu"
cc 'test.o' -o 'test'  -rdynamic  -lncurses -lpcre -lgc -lpthread /usr/local/Cellar/crystal/0.26.1/src/ext/libcrystal.a -levent -lrt -ldl -L/usr/lib -L/usr/local/lib

Resources

• Crystal
• Docs
• API
• Github
• Playground
• Bountysource
• Kemal
• Lucky