n3 - npm Package Compare versions

Comparing version 1.2.1 to 1.3.0

lib/N3Store.js

@@ -12,2 +12,4 @@ "use strict";
 
+var _IRIs = _interopRequireDefault(require("./IRIs"));
+
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
@@ -389,3 +391,2 @@
   match(subject, predicate, object, graph) {
-    var self = this;
     var stream = new _stream.Readable({
@@ -395,11 +396,5 @@ objectMode: true
 
-    stream._read = function () {
-      stream._read = function () {};
+    stream._read = () => {
+      for (var quad of this.getQuads(subject, predicate, object, graph)) stream.push(quad);
 
-      var quads = self.getQuads(subject, predicate, object, graph);
-
-      for (var quad of quads) {
-        stream.push(quad);
-      }
-
       stream.push(null);
@@ -692,2 +687,83 @@ };
     return this._factory.blankNode(name.substr(2));
+  } // ### `extractLists` finds and removes all list triples
+  // and returns the items per list.
+
+
+  extractLists({
+    remove = false,
+    ignoreErrors = false
+  } = {}) {
+    var lists = {}; // has scalar keys so could be a simple Object
+
+    var onError = ignoreErrors ? () => true : (node, message) => {
+      throw new Error(`${node.value} ${message}`);
+    }; // Traverse each list from its tail
+
+    var tails = this.getQuads(null, _IRIs.default.rdf.rest, _IRIs.default.rdf.nil, null);
+    var toRemove = remove ? [...tails] : [];
+    tails.forEach(tailQuad => {
+      var items = []; // the members found as objects of rdf:first quads
+
+      var malformed = false; // signals whether the current list is malformed
+
+      var head; // the head of the list (_:b1 in above example)
+
+      var headPos; // set to subject or object when head is set
+
+      var graph = tailQuad.graph; // make sure list is in exactly one graph
+      // Traverse the list from tail to end
+
+      var current = tailQuad.subject;
+
+      while (current && !malformed) {
+        var objectQuads = this.getQuads(null, null, current, null);
+        var subjectQuads = this.getQuads(current, null, null, null);
+        var i,
+            quad,
+            first = null,
+            rest = null,
+            parent = null; // Find the first and rest of this list node
+
+        for (i = 0; i < subjectQuads.length && !malformed; i++) {
+          quad = subjectQuads[i];
+          if (!quad.graph.equals(graph)) malformed = onError(current, 'not confined to single graph');else if (head) malformed = onError(current, 'has non-list arcs out'); // one rdf:first
+          else if (quad.predicate.value === _IRIs.default.rdf.first) {
+              if (first) malformed = onError(current, 'has multiple rdf:first arcs');else toRemove.push(first = quad);
+            } // one rdf:rest
+            else if (quad.predicate.value === _IRIs.default.rdf.rest) {
+                if (rest) malformed = onError(current, 'has multiple rdf:rest arcs');else toRemove.push(rest = quad);
+              } // alien triple
+              else if (objectQuads.length) malformed = onError(current, 'can\'t be subject and object');else {
+                  head = quad; // e.g. { (1 2 3) :p :o }
+
+                  headPos = 'subject';
+                }
+        } // { :s :p (1 2) } arrives here with no head
+        // { (1 2) :p :o } arrives here with head set to the list.
+
+
+        for (i = 0; i < objectQuads.length && !malformed; ++i) {
+          quad = objectQuads[i];
+          if (head) malformed = onError(current, 'can\'t have coreferences'); // one rdf:rest
+          else if (quad.predicate.value === _IRIs.default.rdf.rest) {
+              if (parent) malformed = onError(current, 'has incoming rdf:rest arcs');else parent = quad;
+            } else {
+              head = quad; // e.g. { :s :p (1 2) }
+
+              headPos = 'object';
+            }
+        } // Store the list item and continue with parent
+
+
+        if (!first) malformed = onError(current, 'has no list head');else items.unshift(first.object);
+        current = parent && parent.subject;
+      } // Don't remove any quads if the list is malformed
+
+
+      if (malformed) remove = false; // Store the list under the value of its head
+      else if (head) lists[head[headPos].value] = items;
+    }); // Remove list quads if requested
+
+    if (remove) this.removeQuads(toRemove);
+    return lists;
   }
@@ -694,0 +770,0 @@

lib/N3Writer.js

@@ -50,3 +50,4 @@ "use strict";
     if (outputStream && typeof outputStream.write !== 'function') options = outputStream, outputStream = null;
-    options = options || {}; // If no output stream given, send the output as string through the end callback
+    options = options || {};
+    this._lists = options.lists; // If no output stream given, send the output as string through the end callback
 
@@ -141,4 +142,9 @@ if (!outputStream) {
     // A blank node or list is represented as-is
-    if (entity.termType !== 'NamedNode') return 'id' in entity ? entity.id : '_:' + entity.value; // Escape special characters
+    if (entity.termType !== 'NamedNode') {
+      // If it is a list head, pretty-print it
+      if (this._lists && entity.value in this._lists) entity = this.list(this._lists[entity.value]);
+      return 'id' in entity ? entity.id : '_:' + entity.value;
+    } // Escape special characters
 
+
     var iri = entity.value;
@@ -198,3 +204,2 @@ if (escape.test(iri)) iri = iri.replace(escapeAll, characterReplacer); // Try to represent the IRI as prefixed name
   addPrefixes(prefixes, done) {
-    // Add all useful prefixes
     var prefixIRIs = this._prefixIRIs,
@@ -204,19 +209,16 @@ hasPrefixes = false;
     for (var prefix in prefixes) {
-      // Verify whether the prefix can be used and does not exist yet
       var iri = prefixes[prefix];
       if (typeof iri !== 'string') iri = iri.value;
+      hasPrefixes = true; // Finish a possible pending quad
 
-      if (/[#\/]$/.test(iri) && prefixIRIs[iri] !== (prefix += ':')) {
-        hasPrefixes = true;
-        prefixIRIs[iri] = prefix; // Finish a possible pending quad
+      if (this._subject !== null) {
+        this._write(this._inDefaultGraph ? '.\n' : '\n}\n');
 
-        if (this._subject !== null) {
-          this._write(this._inDefaultGraph ? '.\n' : '\n}\n');
+        this._subject = null, this._graph = '';
+      } // Store and write the prefix
 
-          this._subject = null, this._graph = '';
-        } // Write prefix
 
+      prefixIRIs[iri] = prefix += ':';
 
-        this._write('@prefix ' + prefix + ' <' + iri + '>.\n');
-      }
+      this._write('@prefix ' + prefix + ' <' + iri + '>.\n');
     } // Recreate the prefix matcher
@@ -223,0 +225,0 @@

package.json

 {
   "name": "n3",
-  "version": "1.2.1",
+  "version": "1.3.0",
   "description": "Lightning fast, asynchronous, streaming Turtle / N3 / RDF library.",
@@ -5,0 +5,0 @@ "author": "Ruben Verborgh <[e-mail]>",

src/N3Store.js

 // **N3Store** objects store N3 quads by graph in memory.
 import N3DataFactory from './N3DataFactory';
 import { Readable } from 'stream';
+import namespaces from './IRIs';
 
@@ -379,12 +380,8 @@ const { toId, fromId } = N3DataFactory.internal;
   match(subject, predicate, object, graph) {
-    var self = this;
     var stream = new Readable({ objectMode: true });
 
     // Initialize stream once it is being read
-    stream._read = function () {
-      stream._read = function () {};
-      var quads = self.getQuads(subject, predicate, object, graph);
-      for (var quad of quads) {
+    stream._read = () => {
+      for (var quad of this.getQuads(subject, predicate, object, graph))
         stream.push(quad);
-      }
       stream.push(null);
@@ -697,2 +694,100 @@ };
   }
+
+  // ### `extractLists` finds and removes all list triples
+  // and returns the items per list.
+  extractLists({ remove = false, ignoreErrors = false } = {}) {
+    var lists = {}; // has scalar keys so could be a simple Object
+    var onError = ignoreErrors ? (() => true) :
+                  ((node, message) => { throw new Error(`${node.value} ${message}`); });
+
+    // Traverse each list from its tail
+    var tails = this.getQuads(null, namespaces.rdf.rest, namespaces.rdf.nil, null);
+    var toRemove = remove ? [...tails] : [];
+    tails.forEach(tailQuad => {
+      var items = [];             // the members found as objects of rdf:first quads
+      var malformed = false;      // signals whether the current list is malformed
+      var head;                   // the head of the list (_:b1 in above example)
+      var headPos;                // set to subject or object when head is set
+      var graph = tailQuad.graph; // make sure list is in exactly one graph
+
+      // Traverse the list from tail to end
+      var current = tailQuad.subject;
+      while (current && !malformed) {
+        var objectQuads = this.getQuads(null, null, current, null);
+        var subjectQuads = this.getQuads(current, null, null, null);
+        var i, quad, first = null, rest = null, parent = null;
+
+        // Find the first and rest of this list node
+        for (i = 0; i < subjectQuads.length && !malformed; i++) {
+          quad = subjectQuads[i];
+          if (!quad.graph.equals(graph))
+            malformed = onError(current, 'not confined to single graph');
+          else if (head)
+            malformed = onError(current, 'has non-list arcs out');
+
+          // one rdf:first
+          else if (quad.predicate.value === namespaces.rdf.first) {
+            if (first)
+              malformed = onError(current, 'has multiple rdf:first arcs');
+            else
+              toRemove.push(first = quad);
+          }
+
+          // one rdf:rest
+          else if (quad.predicate.value === namespaces.rdf.rest) {
+            if (rest)
+              malformed = onError(current, 'has multiple rdf:rest arcs');
+            else
+              toRemove.push(rest = quad);
+          }
+
+          // alien triple
+          else if (objectQuads.length)
+            malformed = onError(current, 'can\'t be subject and object');
+          else {
+            head = quad; // e.g. { (1 2 3) :p :o }
+            headPos = 'subject';
+          }
+        }
+
+        // { :s :p (1 2) } arrives here with no head
+        // { (1 2) :p :o } arrives here with head set to the list.
+        for (i = 0; i < objectQuads.length && !malformed; ++i) {
+          quad = objectQuads[i];
+          if (head)
+            malformed = onError(current, 'can\'t have coreferences');
+          // one rdf:rest
+          else if (quad.predicate.value === namespaces.rdf.rest) {
+            if (parent)
+              malformed = onError(current, 'has incoming rdf:rest arcs');
+            else
+              parent = quad;
+          }
+          else {
+            head = quad; // e.g. { :s :p (1 2) }
+            headPos = 'object';
+          }
+        }
+
+        // Store the list item and continue with parent
+        if (!first)
+          malformed = onError(current, 'has no list head');
+        else
+          items.unshift(first.object);
+        current = parent && parent.subject;
+      }
+
+      // Don't remove any quads if the list is malformed
+      if (malformed)
+        remove = false;
+      // Store the list under the value of its head
+      else if (head)
+        lists[head[headPos].value] = items;
+    });
+
+    // Remove list quads if requested
+    if (remove)
+      this.removeQuads(toRemove);
+    return lists;
+  }
 }
@@ -699,0 +794,0 @@

src/N3Writer.js

@@ -36,2 +36,3 @@ // **N3Writer** writes N3 documents.
     options = options || {};
+    this._lists = options.lists;
 
@@ -133,4 +134,8 @@ // If no output stream given, send the output as string through the end callback
     // A blank node or list is represented as-is
-    if (entity.termType !== 'NamedNode')
+    if (entity.termType !== 'NamedNode') {
+      // If it is a list head, pretty-print it
+      if (this._lists && (entity.value in this._lists))
+        entity = this.list(this._lists[entity.value]);
       return 'id' in entity ? entity.id : '_:' + entity.value;
+    }
     // Escape special characters
@@ -204,20 +209,16 @@ var iri = entity.value;
   addPrefixes(prefixes, done) {
-    // Add all useful prefixes
     var prefixIRIs = this._prefixIRIs, hasPrefixes = false;
     for (var prefix in prefixes) {
-      // Verify whether the prefix can be used and does not exist yet
       var iri = prefixes[prefix];
       if (typeof iri !== 'string')
         iri = iri.value;
-      if (/[#\/]$/.test(iri) && prefixIRIs[iri] !== (prefix += ':')) {
-        hasPrefixes = true;
-        prefixIRIs[iri] = prefix;
-        // Finish a possible pending quad
-        if (this._subject !== null) {
-          this._write(this._inDefaultGraph ? '.\n' : '\n}\n');
-          this._subject = null, this._graph = '';
-        }
-        // Write prefix
-        this._write('@prefix ' + prefix + ' <' + iri + '>.\n');
+      hasPrefixes = true;
+      // Finish a possible pending quad
+      if (this._subject !== null) {
+        this._write(this._inDefaultGraph ? '.\n' : '\n}\n');
+        this._subject = null, this._graph = '';
       }
+      // Store and write the prefix
+      prefixIRIs[iri] = (prefix += ':');
+      this._write('@prefix ' + prefix + ' <' + iri + '>.\n');
     }
@@ -224,0 +225,0 @@ // Recreate the prefix matcher

No alert changes

Improved metrics

Total package byte prevSize

245796

increased by2.96%

Lines of code

5289

increased by2.78%

No dependency changes