URList

URList is a conceptual data structure used to manage collections of Uniform Resource Identifiers (URIs). It is designed to handle storage and manipulation of URIs with features such as deduplication, normalization, and validation, while optionally preserving a defined order.

A URList typically supports core operations such as adding and removing URIs, checking for containment, querying size, and iterating over elements. It may also provide serialization options to formats like JSON or CSV, and can expose hooks for custom processing during insertion (for example, normalization or filtering). Implementations may back the collection with a dynamic array, a linked list, or a hash-based structure to balance memory use and performance.

Normalization and validation are common concerns in URList. Normalization aims to resolve URIs to a canonical form by applying rules such as host name case normalization, percent-encoding normalization, and default port handling. Validation ensures syntactic correctness and may include checks against URL parsing rules or schema suitability. Deduplication ensures that identical URIs are represented once, though some designs allow multiple representations if ordering or provenance requires it.

Use cases for URList include web crawlers, link validators, content indexing, digital libraries, and metadata management where managing large sets of URIs efficiently is important. Implementations vary by language and framework, and practical URLists should document normalization rules, memory considerations, and any privacy implications of storing and manipulating URIs.

URList is related to general data structures such as lists, sets, and queues, and is often implemented as a specialized combination to support both order and uniqueness for URI collections.