Convert SHACL to ShEx

[labra]

Implement a conversion from SHACL-core to ShEx.

The converter has already been started although some features are not implemented yet. We will keep this issue open to track the features that are implemented and the issues found.

Features:

SHACL features based on: SHACL recommendation

Target selection

Simple target selection can be mapped to ShEx shape maps.

| Feature | |
| --- | --- | --- |
| Target Node sh:targetNode | ❌ | Pending shapeMaps conversion |
| Class-based targets sh:targetClass | ❌ | Pending shapeMaps conversion |
| Implicit class targets | ❌ | Pending shapeMaps conversion |
| Subjects of targets sh:targetSubjectsOf | ❌ | Pending shapeMaps conversion |
| Objects of targets sh:targetObjectsOf | ❌ | Pending shapeMaps conversion |

Shapes

Feature	Supported	Comments
sh:name		Could be done with annotations
sh:description		Could be done with annotations
sh:group		Could be done with annotations
sh:order		Could be done with annotations
owl:imports
sh:entailment
sh:shapesGraph

Validation report

Feature	Supported	Pending
sh:deactivated
sh:message
sh:severity

Constraints

Feature	Supported	Pending
Node constraints	✔️
Property shapes (sh:path)	✔️
Path constraints		This feature is not easy to map between ShEx and SHACL

Constraint components

Feature	Supported	Pending	Comments
sh:class
sh:datatype	✔️
sh:nodeKind	✔️
sh:minCount	✔️
sh:maxCount	✔️
sh:minInclusive, sh:maxInclusive, sh:minExclusive, sh:maxExclusive
sh:minLength
sh:maxLength
sh:pattern
sh:flags
sh:languageIn
sh:uniqueLang
sh:equals
sh:disjoint
sh:lessThan			This feature is not easy in ShEx
sh:lessThanOrEquals			This feature is not easy in ShEx
sh:not
sh:and
sh:or
sh:xone
sh:node
sh:qualifiedValueshape, qualifiedMinCount, qualifiedMaxCount
sh:qualifiedValueshapesDisjoint
sh:closed
sh:ignoredProperties
sh:hasValue
sh:in

SPARQL based constraints

(:x:) Non-supported