Identity-based reference wrapper and collection helpers enabling reference-equality keys, identity sets/maps, lazy distinct-by-identity sequences, and diagnostic identity strings for interning, memoization, and cycle detection.
Surfaced from shared tags and platforms — no rankings paid for.
kotlin-data-ref provides small identity-based collection helpers for Kotlin Multiplatform code.
Use it when object identity matters more than structural equality: graph algorithms, object interning, cycle detection, memoization keyed by object references, and diagnostics that need to distinguish equal-but-distinct objects.
commonMain.dependencies {
implementation("one.wabbit:kotlin-data-ref:1.1.1")
}
import one.wabbit.data.Ref
import one.wabbit.data.identitySetOf
data class Node(val id: Int)
val a = Node(1)
val b = Node(1)
check(a == b)
check(Ref(a) != Ref(b))
val nodes = identitySetOf(a, b)
check(nodes.size == 2)
Ref delegates hashing to the platform identity hash code and compares wrapped values with ===.
That makes it suitable as a key when the wrapped type has structural equals/hashCode behavior
that you explicitly do not want.
Ref.toString() is diagnostic-only. For non-null values it includes a platform class name and
unsigned hexadecimal identity hash; for null it returns Ref[null]. The exact output should not be
parsed.
This library is small and stable in scope, but it is still pre-2.0. Public API changes should be rare and documented in release notes.
import one.wabbit.data.identityMap
import one.wabbit.data.identitySetOf
val first = String(charArrayOf('x'))
val second = String(charArrayOf('x'))
val set = identitySetOf(first, second)
check(set.size == 2)
val map = identityMap<String, >()
map[first] =
map[second] =
check(map[first] == )
check(map[second] == )
import one.wabbit.data.distinctByIdentity
val item = Any()
val values = listOf(item, Any(), item)
check(values.distinctByIdentity().size == 2)
The iterable overload returns a List. The sequence overload filters lazily and keeps one identity
set of already-seen references for the duration of iteration.
Generated API docs can be built locally with Dokka. See API reference notes for the command.
This project is licensed under the GNU Affero General Public License v3.0 (AGPL-3.0) for open source use.
For commercial use, contact Wabbit Consulting Corporation at wabbit@wabbit.one.
Contributions are governed by the repository contribution policy and the Wabbit CLA. See
CONTRIBUTING.md and the files under legal/.