2.6.9 New

An allocation operation has the form:

    NEW(T, ...)

where T is a reference type other than REFANY, ADDRESS, or NULL. The operation returns the address of a newly-allocated variable of T's referent type; or if T is an object type, a newly-allocated data record paired with a method suite. The reference returned by NEW is distinct from all existing references. The allocated type of the new reference is T.

It is a static error if T's referent type is empty. If T is declared as an opaque type, NEW(T) is legal only in scopes where T's concrete type is known completely, or is known to be an object type.

The initial state of the referent generally represents an arbitrary value of its type. If T is an object type or a reference to a record or open array then NEW takes additional arguments to control the initial state of the new variable.

If T is a reference to an array with k open dimensions, the NEW operation has the form:

    NEW(T, n_1, ..., n_k)

where the n's are integer-valued expressions that specify the lengths of the new array in its first k dimensions. The values in the array will be arbitrary values of their type.

If T is an object type or a reference to a record, the NEW operation has the form:

    NEW(T, Bindings)

where Bindings is a list of keyword bindings used to initialize the new fields. Positional bindings are not allowed.

Each binding f := v initializes the field f to the value v. Fields for which no binding is supplied will be initialized to their defaults if they have defaults; otherwise they will be initialized to arbitrary values of their types.

The order of the field bindings makes no difference.

If T is an object type then Bindings can also include method overrides of the form m := P, where m is a method of T and P is a top-level procedure constant. This is syntactic sugar for the allocation of a subtype of T that includes the given overrides, in the given order. For example, NEW(T, m := P) is sugar for

    NEW(T OBJECT OVERRIDES m := P END).