PSVec

Indexed access. Unchecked: UB if i < 0 || i >= length.

Read the first element. Unchecked: UB if length == 0.

Zero-copy view [from, until), clamped to this vector's bounds.

Materialise as a fresh Array[Any] (Object[] at runtime) — the erased storage currency of the carrier machinery (ObjArrBuilder, mfAssocPSVec, the schemes fold engine), which has no ClassTag to build typed arrays with. Slice overrides with System.arraycopy (intrinsic) so the common rebuild path in Traversal.pEach's from is one memcpy.

Compares the receiver object (this) with the argument object (that) for equivalence.

Any implementation of this method should be an equivalence relation:

• 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)).

Calculates a hash code value for the object.

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.

Index-walking iterator — the IterableOnce bridge (and what makes a PSVec acceptable anywhere a collection is). Hot paths stay on the index loops.

Deliberately hand-rolled, NOT Iterator.tabulate(length)(apply) — BY MEASUREMENT (2026-07-22, -prof gc): the tabulate version regressed JsoniterBench.jReadId 48 → 72 B/op (+50%) — its lambda-capturing shape perturbs inlining enough to un-elide the generic foldMap closure in forks that merely LOAD this class. Do not re-simplify without re-measuring that bench.

The number of elements in this $coll, if it can be cheaply computed, -1 otherwise. Cheaply usually means: Not requiring a collection traversal.

Materialise as a List — the read-side bridge for Plated.children / universe and the carriers (circe / avro) that reconstruct from an ordered sequence.

Returns a string representation of the object.

The default representation is platform dependent.

Like toAnyArray but MAY share the backing array zero-copy when a dense Slice covers its full range. Callers MUST treat the result as immutable. Used by consumers that also won't mutate, e.g. optics.Traversal.pEach's from → ArraySeq.unsafeWrapArray). Default is the safe copy; only Slice overrides to share.

Returns a scala.collection.Stepper for the elements of this collection.

The Stepper enables creating a Java stream to operate on the collection, see scala.jdk.StreamConverters. For collections holding primitive values, the Stepper can be used as an iterator which doesn't box the elements.

The implicit scala.collection.StepperShape parameter defines the resulting Stepper type according to the element type of this collection.

• For collections of Int, Short, Byte or Char, an scala.collection.IntStepper is returned
• For collections of Double or Float, a scala.collection.DoubleStepper is returned
• For collections of Long a scala.collection.LongStepper is returned
• For any other element type, an scala.collection.AnyStepper is returned

Note that this method is overridden in subclasses and the return type is refined to S with EfficientSplit, for example scala.collection.IndexedSeqOps.stepper. For Steppers marked with scala.collection.Stepper.EfficientSplit, the converters in scala.jdk.StreamConverters allow creating parallel streams, whereas bare Steppers can be converted only to sequential streams.