Should not need '!' for accessing compile-time properties of a field

[vasslitvinov]

This is a more complex pattern than #13617.

When accessing a field of a nilable class, the postfix-! operator should not be required when the use of the field is limited to compile-time operations. This is for convenience.

For example, none of the !s in this code should be required, as there should be no runtime nil checks. It is more convenient to omit them.

class C1 {
  var x: int;
  var y;     // a generic field
}

class C2 {
  param p;
  type t;
}

var c: owned C1(owned C2(5,int)?)?;

// the type of a field
writeln(c!.x.type:string, c!.y.type:string);

// type, param queries on the class pointed to by a field
writeln(c!.y.p:string, c!.y.t:string);

Example test:

# see proc getSuperType()
test/classes/diten/nearestMutualParentClass.chpl

[bradcray]

@vasslitvinov: I have a vague memory from the CHANGES file that you implemented this, is that right? Can it be closed?

[vasslitvinov]

Good point. My implementation resolved #13617. The examples in this issue are more complex than that and currently still require !.

So no, this issue is not resolved yet.