Attributes declaration

Attributes can be declared in :

The list of typed arguments that follow the name
As fields directly in the module body

Attributes declared in the the list of typed arguments are used implicitly for both: the constructor, and the pattern.

All attributes implicitly declare their accessors.

Attribute accessors are the methods to get and set the attribute value. The accessors of a Node are automatically resolved by the compiler with the syntax:

Sphere s; // has an attribute diameter
s[diameter] = 5; // automatically resolve the setter
float d = s[diameter]; // automatically resolve the getter

module A (float len); // is equiavent to:
class A extends Node {
 
float len;
 
public A(float l) { len = l; }
 
public static class Pattern extends UserDefinedPattern {
  private static void signature(@In @Out X node,
                                              float len ) {}
  }
}