Public utility classes

A small set of utility classes is exported alongside JsonTology for advanced use - cases where you reach below the facade for graph, RDF, or hashing primitives. Each utility has one responsibility.

Class	Module	Purpose
Curie	src/modules/rdf/Curie.ts	Compact / expand IRIs against a prefix map
Path	src/modules/data/Path.ts	Convert JSON Pointers to JS access form
Resolver	src/modules/data/Resolver.ts	Merge per-call options with a base options object
Hash	src/modules/hash/Hash.ts	Deterministic FNV-1a hash of any JSON-serializable value
Lift	src/modules/rdf/Lift.ts	RDF interop helpers (RDF/JS quad conversion, lifting)

The bookstore domain in Bookstore Domain supplies prefixes and IRIs in the snippets.

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Curie

new Curie(prefixes) returns a CURIE handler. compact(iri) shrinks a full IRI; expand(curie) resolves a compact form back to a full IRI.

import { Curie } from 'json-tology';

const curie = new Curie({
  bk:  'https://bookstore.example/',
  xsd: 'http://www.w3.org/2001/XMLSchema#',
});

curie.compact('https://bookstore.example/Book');  // 'bk:Book'
curie.expand('bk:Book');                          // 'https://bookstore.example/Book'
curie.expand('xsd:string');                       // 'http://www.w3.org/2001/XMLSchema#string'

When multiple prefixes share an overlap, compact picks the longest match.

Path

Path.toAccess(jsonPointer) converts a JSON Pointer into JS access form - the path you would write to read the value out of the object. Useful when surfacing validation errors in UIs that expect access notation.

import { Path } from 'json-tology';

Path.toAccess('/items/0/quantity');  // 'items[0].quantity'
Path.toAccess('/customer/name');     // 'customer.name'
Path.toAccess('/oddly-shaped-key');  // '["oddly-shaped-key"]'
Path.toAccess('');                   // ''

Numeric segments become [N]; identifier-shaped segments become .name; non-identifier segments are quoted with bracket notation.

Resolver

Resolver.merge(base, override) returns a fresh object with override's defined keys overwriting base. undefined keys in override do not erase base values - this is the per-call option-merge pattern used throughout json-tology.

import { Resolver } from 'json-tology';

const base = { enableDefaults: true, enableValidation: true };
const merged = Resolver.merge(base, { enableDefaults: false });
// { enableDefaults: false, enableValidation: true }

Resolver.merge(base, { enableDefaults: undefined });
// { enableDefaults: true, enableValidation: true }

Hash

Hash.value(input) returns a hex FNV-1a hash. Object keys are sorted before serialization, so two objects that differ only in key order produce the same hash.

import { Hash } from 'json-tology';

Hash.value({ isbn: '9780140449136', title: 'War and Peace' });
// 'abc12345' (deterministic, hex)

Hash.value({ title: 'War and Peace', isbn: '9780140449136' }) ===
  Hash.value({ isbn: '9780140449136', title: 'War and Peace' });
// true - key order does not matter

Used internally by registerAnonymous to mint synthetic $id values from schema content. Use it directly when you need a stable cache key for a structured value.

Lift

The Lift module exposes interop helpers between RDF/JS quads (from libraries like n3 or eyereasoner) and json-tology's internal quad shape, plus the liftInstances function that powers JsonTology.fromQuads.

import { fromRdfQuad } from 'json-tology';
import type { QuadInterface } from 'json-tology/types';

// rdfQuads from an external RDF/JS source (e.g. n3.Parser)
const internal: QuadInterface[] = rdfQuads.map(fromRdfQuad);

// pass to JsonTology.fromQuads
const books = entities.fromQuads('https://bookstore.example/Book', internal);

For the typed round-trip use the JsonTology facade (RDF round-trip). Reach for Lift only when integrating with an external RDF/JS library directly.

Related

• RDF round-trip - toQuads / fromQuads use these utilities under the hood
• Graph concepts - canonical graph structure

See also

• Bookstore domain - schema definitions referenced in snippets