Crate haystack_core 

Haystack Core

Rust implementation of the Project Haystack data model, codecs, filter engine, entity graph, ontology system, and SCRAM SHA-256 authentication.

Crate Organization

Module	Description
kinds	Central value type (Kind) with 15 scalar types (Marker, Number, Str, Ref, etc.)
data	Collection types: HDict (tag map), HGrid (table), HCol, HList
codecs	Wire format codecs: Zinc, Trio, JSON, Haystack JSON v3, CSV, and RDF (Turtle/JSON-LD)
filter	Haystack filter expression parser and evaluator (site and area > 1000)
graph	In-memory entity graph with bitmap tag indexes, B-tree value indexes, ref adjacency, CSR, and change tracking
ontology	Haystack 4 def/lib/namespace system with taxonomy, validation, and Xeto support
auth	SCRAM SHA-256 authentication per the Haystack auth specification
xeto	Xeto schema language parser and structural type fitting

Quick Start

use haystack_core::data::{HDict, HGrid};
use haystack_core::kinds::{Kind, Number, HRef};
use haystack_core::graph::EntityGraph;
use haystack_core::codecs::codec_for;

// Build an entity
let mut site = HDict::new();
site.set("id", Kind::Ref(HRef::from_val("site-1")));
site.set("dis", Kind::Str("Main Campus".into()));
site.set("site", Kind::Marker);
site.set("area", Kind::Number(Number::unitless(50000.0)));

// Add to graph and query
let mut graph = EntityGraph::new();
graph.add(site).unwrap();
let results = graph.read_all("site and area > 1000", 0).unwrap();
assert_eq!(results.len(), 1);

// Encode to Zinc wire format
let zinc = codec_for("text/zinc").unwrap();
let grid = graph.to_grid("").unwrap();
let encoded = zinc.encode_grid(&grid).unwrap();

Modules

auth

SCRAM SHA-256 authentication primitives for the Haystack auth protocol.

codecs

Haystack wire format codecs for serialization and deserialization.

data

Haystack data collection types.

filter

Haystack filter expression parser and evaluator.

graph

In-memory entity graph with indexed querying, change tracking, and thread-safe access.

kinds

Haystack type system — the Kind enum and its 15 scalar types.

ontology

Haystack 4 ontology layer — defs, taxonomy, conjuncts, and validation.

xeto