Provides general-purpose maps with support to prefix queries. This module defines the following interfaces: - [[PrefixMap]], an immutable [`SortedMap`](https://modules.ceylon-lang.org/repo/1/ceylon/collection/1.2.0/module-doc/api/SortedMap.type.html) that supports prefix queries and is keyed by streams of [[Comparable]] objects; - [[TernaryTreeMap]], a mutable [[PrefixMap]] backed by a ternary search tree. [[TernaryTreeMap]] is an abstract supertype for the following ...