Crate datafox 

Datafox is a standalone Datalog parser and streaming query engine for facts.

The crate is intentionally small: callers provide facts through Storage, parse read-only queries with parse_query or parse_queries, and evaluate them with a DatafoxClient configured for the runtime profile you need.

use datafox::{DatafoxClient, DatafoxConfig, InMemoryStorage, Value, parse_query};

let storage = InMemoryStorage::from_facts([(
    "edge".to_string(),
    vec![
        vec![Value::integer(1), Value::integer(2)],
        vec![Value::integer(2), Value::integer(3)],
    ],
)]);
let query = parse_query("edge(From, 2)")?;
let datafox = DatafoxClient::new(DatafoxConfig::new(&storage))?;
let results = datafox.eval(&query)?.collect::<Vec<_>>();

assert_eq!(results.len(), 1);
assert_eq!(results[0].lookup("From"), Some(&Value::integer(1)));

Public API:

• Value for Datalog constants.
• Term for variables, constants, and wildcards.
• Atom, Clause, and Query for query syntax trees.
• Diagnostic and parse_query for query parsing with context.
• format_query and format_queries for stable, readable query files.
• Substitution and Unifier for binding and matching query variables.
• DatafoxClient, DatafoxConfig, DatafoxEnvironment, PreparedQuery, PreparedQueryStorage, Planner, Plan, and Storage for snapshot-based query execution.
• Prelude, BinaryRelation, and BinaryOperator for ambient facts, builtin relations, and expression operators.
• Error and Result for typed failures.
• atom!, var!, lit!, and subst! for test and call-site ergonomics.

Re-exports

pub use error::Error;

pub use error::Result;

Modules

error

Macros

atom

lit

subst

var

Structs

Atom

A predicate applied to a list of terms.

BinaryOperator

BinaryRelation

DatafoxClient

DatafoxConfig

DatafoxEnvironment

DatafoxEnvironmentBuilder

Diagnostic

One contextual parser or analyzer diagnostic.

Evaluation

Iterator over substitutions produced by an evaluator run.

FactEstimate

FactRequest

FactRequestHints

InMemoryPreparedQueryStorage

InMemoryStorage

Planner

Prelude

PreparedQuery

PreparedQueryKey

Span

One source span in an input query string.

Substitution

A deterministic mapping from variable names to concrete values.

Unifier

Stateless helpers for unification and atom-to-tuple matching.

Universe

A read-only query snapshot over a storage backend.

Enums

AtomRole

Clause

One clause in a query body.

EvaluationStrategy

FactRequestMode

FactScan

OperatorOutcome

PatternValue

Projection

Query

A read-only Datalog query.

RelationOutcome

SnapshotSelector

Term

One Datalog term.

Value

Concrete constant values that can appear in Datalog facts and queries.

Constants

PREPARED_QUERY_FORMAT_VERSION

Traits

FactStore

PreparedQueryStorage

Storage

Snapshot-oriented read-only storage interface for Datalog queries.

Functions

format_queries

format_query

matches_pattern

parse_queries

parse_query

Type Aliases

FactTuple

Plan

PlanningCache

TupleStream