control structures:
  - skip
  - while, do-while
  - labeled loops
  - dangling else?
  - let
  - case guards
  - "as" in patterns
  
structures:
  - struct, struct init, struct copy, struct field access
  - opt_struct
  - struct patterns
  
other type stuff:
  - tuples
  - type
  - typedef
  
special datatypes:
  - list
  - option
  - char

language constructs:
  - unnamed function arguments
  - bit operators
  - ++, --, +=, etc
  - extern (in and out)

- polimorphism...
- type inferrence: _, fun (s) (s.foobar), def x(...)
