Type variable have two forms: when id is not set, that means that for each instantiation of type-lambda, a new set of type-variables with fresh id-s are created. when id is set, that means that computations are situated in the process of instantiation of some type-lambda.
Equality (equals/hashCode) deliberately ignores kind — substitution and unification key on identity (name, optId), while kind is semantic metadata about the representation policy. A Transparent and an Unwrapped TypeVar with the same (name, optId) are the SAME variable from substitution's point of view, differing only in how lowering picks its runtime representation.
Not a case class because the auto-generated equals/hashCode include every field; custom apply/unapply/copy are provided for source-level compatibility.
Value parameters
kind
controls representation during lowering. See TypeVarKind.
It is reflexive: for any instance x of type Any, x.equals(x) should return true.
It is symmetric: for any instances x and y of type Any, x.equals(y) should return true if and only if y.equals(x) returns true.
It is transitive: for any instances x, y, and z of type Any if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
If you override this method, you should verify that your implementation remains an equivalence relation. Additionally, when overriding this method it is usually necessary to override hashCode to ensure that objects which are "equal" (o1.equals(o2) returns true) hash to the same scala.Int. (o1.hashCode.equals(o2.hashCode)).
Value parameters
that
the object to compare against this object for equality.
Attributes
Returns
true if the receiver object is equivalent to the argument; false otherwise.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)) yet not be equal (o1.equals(o2) returns false). A degenerate implementation could always return 0. However, it is required that if two objects are equal (o1.equals(o2) returns true) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals method.
Backward-compatible check: true only for Transparent ("unknown — will be substituted at inline time"). Unwrapped, like Fixed, is a CONCRETE target form (concrete type's default repr); it requires conversion at boundaries, not passthrough relabeling.
Backward-compatible check: true only for Transparent ("unknown — will be substituted at inline time"). Unwrapped, like Fixed, is a CONCRETE target form (concrete type's default repr); it requires conversion at boundaries, not passthrough relabeling.