Feature support

Legend: ✅ supported · ⚠️ partial or gated · ❌ unsupported.

The pinned SHACL 1.0 suite and reporting procedure are described in Run the W3C SHACL suite. Test results cover the cases in that suite; the feature descriptions below also identify extension-specific limits.

SHACL Core

Feature	Status	Notes
Node & property shapes	✅
Targets — targetNode, targetClass, targetSubjectsOf, targetObjectsOf, implicit class	✅
Cardinality — minCount, maxCount	✅
Value type — datatype, nodeKind, class	✅
Range — min/maxInclusive, min/maxExclusive	✅	numeric, date/time, and duration ordering
String — minLength, maxLength, pattern (+ flags), languageIn, uniqueLang	✅
Logical — and, or, not, xone	✅
Shape-based — node, property, qualifiedValueShape (+ counts, qualifiedValueShapesDisjoint)	✅
Property pairs — equals, disjoint, lessThan, lessThanOrEquals	✅	on node and property shapes
Other — closed (+ ignoredProperties), hasValue, in	✅
Paths — predicate, inverse, sequence, alternative, zeroOrMore, oneOrMore, zeroOrOne	✅
severity, deactivated, message	✅

SHACL-SPARQL

Feature	Status	Notes
SPARQL constraints — sh:sparql (sh:select)	✅	native execution with Spareval fallback
Custom constraint components — sh:parameter + sh:validator / sh:nodeValidator / sh:propertyValidator	✅	optional params, simple and complex $PATH, report path

SHACL-AF (Advanced Features)

Feature	Status	Notes
Rules — sh:TripleRule, sh:SPARQLRule (CONSTRUCT)	✅	forward-chained to a fixed point, honouring sh:order / sh:condition
Node expressions — sh:this, constants, sh:path, sh:filterShape, sh:intersection, sh:union, function application	✅
SPARQL targets — sh:target + sh:select	✅
Expression constraints — sh:expression	✅
SHACL functions — sh:SPARQLFunction in node expressions	✅	full data-graph access
SHACL functions — sh:SPARQLFunction called from SPARQL (sh:sparql, CONSTRUCT, dash:expression)	⚠️	evaluated as pure functions of their arguments; a body that reads the data graph is gated — see Partial support
JavaScript — sh:js*, sh:JSFunction	❌	no JS engine

Recursion and semantics

Feature	Status	Notes
Stratified recursive shapes	✅	greatest fixed point for validation, least for inference, per stratum
Non-stratifiable schemas (a cycle through negation)	❌	diagnosed and refused, never guessed

See Recursive shapes for the recursion policy.

Partial support

A ⚠️ feature has partial support and may produce incorrect results. on_unsupported controls how these features are handled. It is set through EngineOptions in Rust, and a keyword on validate, validate_algebra, infer, and PreparedValidator in Python:

"ignore"

Best effort. A graph-reading function called from a SPARQL context is evaluated over an empty dataset, so the result may be wrong.

"error" (default)

Refuse. The unsupported construct surfaces as a failure instead of a silent wrong answer.

conforms, report, text = shifty.validate(data, shapes, on_unsupported="error")

Invalid shapes diagnostics are separate from this policy. A malformed SHACL constraint or rule, including malformed SPARQL or an unresolved query prefix, is always rejected before validation or inference starts; it is never lowered as an absent feature.

Use "error" when an unsupported feature should stop validation.

Evidence and repair coverage

Structural explanations are not always available: a sh:sparql constraint is opaque to evidence and blocked for repair, because an arbitrary query cannot be inverted. The complete list of these cases is in Evidence reference under “Opaque and blocked evidence”, and repair’s blocking reasons are in Repair reference.