Proposal for new syntax for type definition. Motivation: Rust tries to mix concepts from Functional languages with syntax from C/C++. structs (records) are equivalent to the C/C++ version. However enums in rust do not behave like enums from c: Enums in rust are used to define Algebraic Data Types (sum types) that act similar to 'tagged unions' i…

RustSyntaxProposal

type Name = {
  first: ~str,
  last:	~str
}
 
 
type Shape = Circle(int) | Rect(int, int)	// Variants with constructors
 
type Direction = North | South | East | West	// without constructors
 
enum Flags = {
  Optimise = 1,
  Debug = 2,
  Assemble = 4,
  Default = Optimise | Debug
}
 
type Point = (int, int)			// Tuples with name can replace tuple-structs
 
 
fn stream<T> () -> (Port<T>, Chan<T>); 	// tuples with no name can be used for
					// returning multiple values
 
 
type Coordinate = Point			// alias or typedef
 
 
 
type Celcius = (float)		//tuple with one element can be used as haskell newtype
type Kelvin  = (float)
 
fn celcius_to_kelvin(cel: Celcius) -> Kelvin {
  return *cel + 273.0f;
}
 
 
fn main() {
  
  let name = Name{first: ~"John", last: ~"Smith"};
  let shape  = @Circle(20);
  let point = Point(10,20);
 
  let flags = Flags.Optimise     // this is why we have seperate enum keyword.
  
  let temp = Celcius(0);	 // looks like constructor and matches the type definition
  let temp = celcius_to_kelvin(temp);
 
}