perstring

Perstring is a term encountered in discussions of string processing and data representation. It refers to a string data structure or concept that associates auxiliary per-character information with each character in the string. This per-character metadata may include attributes such as font, color, encoding flags, or other annotations, allowing operations to consider character-specific properties without creating separate data copies.

Origin and usage: The term is informal and lacks a formal definition in major standards. It arose in programming and text-processing communities in the 2010s and 2020s as a way to discuss efficient handling of annotated text. Different projects may implement perstring concepts with varying details, reflecting practical needs rather than a universal specification.

Characteristics and implementation: In practice, a perstring can be implemented by pairing a character array with a parallel metadata array or by extending the string type with a per-character attribute slice. Access patterns typically involve synchronized iteration over characters and their attributes. Benefits include localized storage of attributes, potential reductions in copying during transformations, and easier implementation of per-character rendering or highlighting. Drawbacks include increased memory overhead, cache locality concerns, and interoperability challenges with APIs that expect plain strings.

Applications: Perstrings are discussed in contexts such as text editors with syntax highlighting, rich-text processing, and annotation or labeling pipelines that require per-character metadata. They are also considered in scenarios where large-scale text processing must preserve styling, encoding flags, or other per-character annotations without duplicating content.

See also: String, Metadata, Rich text, Text rendering.