This project is part of the @thi.ng/umbrella monorepo.
Datalog-inspired, optimized pattern/predicate query engine for JS objects.
ALPHA - bleeding edge / work-in-progress
- @thi.ng/rstream-query - @thi.ng/rstream based triple store & reactive query engine
yarn add @thi.ng/oquery// ES module
<script type="module" src="https://unpkg.com/@thi.ng/oquery?module" crossorigin></script>
// UMD
<script src="https://unpkg.com/@thi.ng/oquery/lib/index.umd.js" crossorigin></script>Package sizes (gzipped, pre-treeshake): ESM: 825 bytes / CJS: 881 bytes / UMD: 943 bytes
TODO - Please see extensive tests for now...
There're 64 possible query approaches, each based on RDF-style Subject-Predicate-Object patterns (only without requiring query terms to be URIs). Each term can be one of:
null- wildcard, any non-null value in that position will be selected- Predicate function - called with all possible terms in that position
- Literal value - for subjects and predicates, this can only be a string or number. For "object" position any value type is allowed
- Array or
Set- multiple choices (literals) for given query term
import { defQuery } from "@thi.ng/oquery";
// object to query
const DB = {
alice: {
age: 33,
knows: ["bob", "charlie", "dori"],
type: "person",
},
bob: {
age: 32,
knows: ["alice"],
type: "person",
spouse: "alice",
},
charlie: {
parent: "alice",
knows: ["alice", "bob", "dori"],
},
};
// init w/ default opts
// (uses @thi.ng/equiv for equality checks)
const query = defQuery();
// find all subjects with `type = "person"` relationship
query(DB, null, "type", "person");
// { alice: { type: 'person' }, bob: { type: 'person' } }
// find all who know bob or charlie
query(DB, null, "knows", ["bob", "charlie"])
// { alice: { knows: [ 'bob', 'charlie' ] }, charlie: { knows: [ 'bob' ] } }
// everyone w/ given min age
query(DB, null, "age", (age) => age >= 33)
// { alice: { age: 33 } }
// select only subjects with A/B initials
query(DB, (id) => id > "a" && id < "c", null, null)
// {
// alice: { age: 33, knows: [ 'bob', 'charlie', 'dori' ], type: 'person' },
// bob: { age: 32, knows: [ 'alice' ], type: 'person', spouse: 'alice' }
// }Karsten Schmidt
© 2020 Karsten Schmidt // Apache Software License 2.0