@shexjs/visitor

[![NPM Version](https://badge.fury.io/js/@shexjs%2Fvisitor.png)](https://npmjs.org/package/shex) [![ShapeExpressions Gitter chat https://gitter.im/shapeExpressions/Lobby](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/shapeExpressions/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.1213693.svg)](https://doi.org/10.5281/zenodo.1213693) # @shexjs/visitor Visitor pattern for traversing [ShExJ](https://shex.io/shex-semantics/#shexj) schemas ## install ``` shell npm install --save @shexjs/visitor ``` ## Quick Start The default behavior is to return a copy of the passed schema: ``` sh 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](http://shex.io/shex-semantics/index.html#shexj) or [Typescript](https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/shexj/index.d.ts). 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](https://github.com/lerna/lerna) to manage multiple NPM packages. These packages are located in `packages/*`: - [`shape-map`](../shape-map#readme) -- a [ShapeMap](https://shexspec.github.io/shape-map/) parser - [`@shexjs/parser`](../shex-parser#readme) -- parse ShExC into ShExJ - [`@shexjs/writer`](../shex-writer#readme) -- serialize ShExK as ShExC - [`@shexjs/term`](../shex-term#readme) -- RDF terms uses in ShEx - [`@shexjs/util`](../shex-util#readme) -- some utilities for transforming schemas or validation output - [`@shexjs/visitor`](../shex-visitor#readme) -- a [visitor](https://en.wikipedia.org/wiki/Visitor_pattern) for schemas - [`@shexjs/validator`](../shex-validator#readme) -- validate nodes in an RDF graph against shapes in a schema - [`@shexjs/eval-validator-api`](../eval-validator-api#readme) -- API called by [`@shexjs/validator`](../shex-validator#readme) for validating Shapes, with tripleExpressions and EXTENDS etc. - [`@shexjs/eval-simple-1err`](../eval-simple-1err#readme) -- Implementation of [`@shexjs/eval-validator-api`](../eval-validator-api#readme) which reports only one error. - [`@shexjs/eval-threaded-nerr`](../eval-threaded-nerr#readme) -- Implementation of [`@shexjs/eval-validator-api`](../eval-validator-api#readme) which exhaustively enumerate combinations of ways the data fails to satisfy a shape's expression. - [`@shexjs/loader`](../shex-loader#readme) -- an API for loading and using ShEx schemas - [`@shexjs/node`](../shex-node#readme) -- additional API functionality for a node environment - [`@shexjs/cli`](../shex-cli#readme) -- a set of command line tools for transformaing and validating with schemas - [`@shexjs/webapp`](../shex-webapp#readme) -- the shex-simple WEBApp - [`@shexjs/shape-path-query`](../shex-shape-path-query#readme) -- traverse ShEx schemas with a path language - [`@shexjs/extension-test`](../extension-test#readme) -- a small language for testing semantic actions in ShEx implementations ([more](http://shex.io/extensions/Test/)) - [`@shexjs/extension-map`](../extension-map#readme) -- an extension for transforming data from one schema to another ([more](http://shex.io/extensions/Map/)) - [`@shexjs/extension-eval`](../extension-eval#readme) -- simple extension which evaluates Javascript semantic action code ([more](http://shex.io/extensions/Eval/))