This package defines traits and abstract types for the essential concepts of the CITE architecture.

Essential concepts

Behaviors of citable resources

The CITE architecture can be described by four kinds of behavior, corresponding in Julia to four traits or interfaces.

  1. identification. Scholarly resources are identified using the syntax of the IETF URN specification, and have a human-readable label. This is expressed by implementing the CitableTrait.
  2. comparison. Citable resources can be compared using the URN logic of equality, containment and similarity. This is expressed by implementing the UrnComparisonTrait.
  3. serialization. Citable resources can be losslessly serialized to plain-text representation in CEX format and instantiated from the same plain-text representation. This is expressed by implementing the CexTrait.
  4. iteration. Collections of citable content can be processed sequentially. This is expressed by implementing the iterators interface from Julia's Iterators module.

Abstractions of essential types

Using these building blocks, the CitableBase further defines three core abstractions:

  1. an identifier uniquely identifies scholarly resources using the syntax of the IETF URN specification. This is represented by the Urn abstract type, and requires implementing the UrnComparisonTrait.
  2. a citable entity is a discrete object identified by a URN. This is represented by the Citable abstract type, and requires implementing the CitableTrait, UrnComparisonTrait, and CexTrait.
  3. a citable collection is a collection of content identifiable by URN. Unlike identifiers and citable entities, they do not fall within a single type hierarchy, and are not represented by subtyping an abstract type. Instead, they are identified by the CitableCollectionTrait, and implement the UrnComparisonTrait, CexTrait and Iterators.
An illustration: the CitableCorpus package

Some citable collections might additionally implement the CitableTrait, in effect making them simultaneously a discrete citable obect (the collection as a whole), and a collection with citable content. The CitableCorpus package illustrates these distinctions handily. Its CitablePassage is a citable object representing a single passage of text. The CitableDocument is both a citable object with its own URN and label, and a collection of citable passages. The CitableCorpus is a pure citable collection of citable documents and citable passages, but does not have its own distinct identifier and label: it is purely a container type.

Contents of this user's guide

It is perfectly possible to use packages implementing the abstractions of CitableBase without understanding how CitableBase is designed. This user's guide is for anyone who needs to build their own custom implementations or simply wishes to understand how these abstractions can be implemented.

The guide works through a hypothetical example to design a reading list of books citable by URN values. The guide first illustrates how to implement a custom URN type for ISBN-10 numbers. It then creates a custom citable object for books cited by ISBN-10 numbers, and finally defines a custom citable collection representing a reading list.

Following the user's guide, the documentation includes the formal API documentation for the exported functions and types of the CitableBase package.