TOC

• similarities
• CLOSED vs. OPEN properties
• shex minus shacl
• shacl minus shex
• funny bits
• JSON structure
• strategy

similarities

• schema is a collection of shapes
• shape is a potentially CLOSED expression
• expression is:
  • triple constraint
  • AND(expression+)
  • OR(expression+)
  • repetition(expression)
• triple constraint fixed constraint and a value class which is N of:
  • node kind: URI, BNODE, LITERAL, NONLITERAL
  • referenced shape: @<PersonShape>
  • xsd facets: length, numeric range, regex
  • value set: ("1" ex:1 sct:~)
• inheritance

CLOSED vs. OPEN properties

<AuthorShape> {
    pub:authored @<ChapterShape>+
}

<Author1> pub:authored <Chapter1>,  <Chapter2>, <SomeBlurb>, <#$%@#$%>.

<Author1> pub:authored <Chapter1>,  <Chapter2>, <SomeBlurb>, <#$%@#$%>.

<AuthorShape> {
    pub:authored @<ChapterShape>+,
    pub:authored @<BlurbShape>
}

<Author1> pub:authored <Chapter1>,  <Chapter2>, <SomeBlurb>, <#$%@#$%>.

<Author1> pub:authored <Chapter1>,  <Chapter2>, <SomeBlurb>, <#$%@#$%>.

<AuthorShape> EXTRA pub:authored {
    pub:authored @<ChapterShape>+,
    pub:authored @<BlurbShape>
}

<Author1> pub:authored <Chapter1>,  <Chapter2>, <SomeBlurb>, <#$%@#$%>.

shex minus shacl

• partition of multi-occurance predicates
• repeated groups
• IRI stems
• addressable value classes
• semantic actions
• inclusion
• EXTRA predicates

shacl minus shex

• conjunction of multi-occurance predicates
• global scope
• templates
• .
• .
• .

funny bits

• shape names in different planes than value set names
• :p1 (ex:~) ≡ :p1 IRI PATTERN "^http://ex\.example/"

JSON syntax

repo

{
  "type": "schema",
  "prefixes": {},
  "shapes": {
    "http://a.example/IssueShape": {
      "type": "shape",
      "expression": {
        "type": "someOf",
        "expressions": [
          {
            "type": "tripleConstraint",
            "predicate": "http://a.example/p1",
            "value": { "type": "valueClass" }
          },
          {
            "type": "tripleConstraint",
            "predicate": "http://a.example/p2",
            "value": { "type": "valueClass" }
          }
        ]
      }
    }
  }
}

strategy

1. document ShEx-to-json à la
   • SPARQL §18.2 parse-tree-to-algebra tables
   • or Turtle §7.2 term constructors
2. transmute the tree to eliminate the upper list
3. ...