@shexjs/visitor
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1.0.0-alpha.27 • Public • Published

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@shexjs/visitor

Visitor pattern for traversing ShExJ schemas

install

npm install --save @shexjs/visitor

Quick Start

The default behavior is to return a copy of the passed schema:

node -e 'console.log(JSON.stringify(new (require("@shexjs/visitor"))()
  .visitSchema(
    {
      "type": "Schema",
      "shapes": [
        {
          "id": "http://a.example/S1",
          "type": "Shape",
          "expression": {
            "type": "TripleConstraint",
            "predicate": "http://a.example/p1",
            "valueExpr": {
              "type": "NodeConstraint",
              "values": [
                {
                  "value": "1",
                  "type": "http://www.w3.org/2001/XMLSchema#integer"
                },
                {
                  "value": "2",
                  "type": "http://www.w3.org/2001/XMLSchema#integer"
                }
              ]
            }
          }
        }
      ]
    }), null, 2))'

The result is will look identical to the input schema

Strategy

The ShExJ format is defined in JSG or Typescript. The visitor API reflects both the names of the ShExJ attributes and their types. For example, by default, the visitShapeAnd calls visitShapeExpr on each of the conjuncts. Likewise, visitTripleConstraint calls visitValueExpr on the .valueExpr attribute, which in turn calles visitShapeExpr because that is the type of .valueExpr.

Methods

  • visitSchema(schema, ...args
  • visitPrefixes(prefixes, ...args
  • visitIRI(i, ...args
  • visitImports(imports, ...args
  • visitStartActs(startActs, ...args
  • visitSemActs([semActs], ...args
  • visitSemAct(semAct, label, ...args
  • visitAnnotations([annotations], ...args
  • TODO visitAnnotation(annotation, ...args
  • visitShapes(shapes, ...args
  • visitShapeDecl(decl, ...args
  • visitShapeExpr(expr, ...args - calls one of the following
    • visitShapeOr(shapeExpr, ...args
    • visitShapeAnd(shapeExpr, ...args
    • visitShapeNot(expr, ...args
    • visitShapeRef(reference, ...args
    • visitShapeExternal(expr, ...args
    • visitNodeConstraint(shape, ...args
    • visitShape(shape, ...args
  • visitExtra([extra], ...args
  • visitExpression(expr, ...args - calls visitTripleExpr
  • visitTripleExpr(expr, ...args - calls one of the following
    • visitOneOf(tripleExpr, ...args
    • visitEachOf(tripleExpr, ...args
    • visitTripleConstraint(expr, ...args
  • visitValueExpr(shapeExpr, ...args
  • visitValues(values, ...args
  • visitValueExpr(shapeExpr, ...args
  • visitStemRange(t, ...args
  • visitExclusion(c, ...args
  • visitInclusion(inclusion, ...args

simple value visitors

  • visitBase
  • visitStart
  • visitClosed
  • "visit@context"
  • visitInverse
  • visitPredicate
  • visitName
  • visitId
  • visitCode
  • visitMin
  • visitMax
  • visitType
  • visitNodeKind
  • visitDatatype
  • visitPattern
  • visitFlags
  • visitLength
  • visitMinlength
  • visitMaxlength
  • visitMininclusive
  • visitMinexclusive
  • visitMaxinclusive
  • visitMaxexclusive
  • visitTotaldigits
  • visitFractiondigits
  • visitInclude

index(schema)

The index function creates a visitor and overrides visitExpression and visitShapeExpr to provide an index composed of two maps:

  • shapeExprs - map from shape declaration name to definition in schema,
  • tripleExprs - map from triple expression name to definition in schema.

Lerna Monorepo

This repo uses lerna to manage multiple NPM packages. These packages are located in packages/*:

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Install

npm i @shexjs/visitor

Weekly Downloads

360

Version

1.0.0-alpha.27

License

MIT

Unpacked Size

63.4 kB

Total Files

10

Last publish

Collaborators

  • ericprud
  • justinwb