added improved discrimators

2026-09-27 15:56:31 +02:00
parent b1fa1d1cd2
commit 538a2d949e
6 changed files with 137 additions and 93 deletions
--- a/src/llm/describe.js
+++ b/src/llm/describe.js
@@ -23,6 +23,7 @@ sh:targetClass is the full URI in brackets after the entity below.
 In sh:path, use the predicate URI shown after each field name, not the field name itself.
 An inverse hop (the field shows "(inverse)") goes in the list as [ sh:inversePath <predicate> ] .
 When two entities share one sh:targetClass, pick one with rep:entity <the URI after the entity>.
+A field that links to several entities ("→ a or b") reaches all of them; the steps after it decide. To keep one kind, add a rep:where on a step only that kind has.
 A date filter is sh:minInclusive or sh:maxInclusive with "yyyy-mm-dd"^^xsd:dateTime
 (the xsd prefix above is not copied: add @prefix xsd: <http://www.w3.org/2001/XMLSchema#>).
 `];
@@ -31,7 +32,7 @@ A date filter is sh:minInclusive or sh:maxInclusive with "yyyy-mm-dd"^^xsd:dateT
    for (const f of shape.fields) {
      const kind = f.datatype ? datatypeName(f.datatype)
        : f.class ? `→ ${conceptLabel(f.class, await codeList(f.class))}`
-        : f.node ? `→ ${linkedLabel(profile, f.node)}`
+        : f.nodes.length ? `→ ${f.nodes.map(n => linkedLabel(profile, n)).join(' or ')}`
        : '?';
      const dir = f.inverse ? ' (inverse)' : '';
      const pathShown = f.path || '?';
--- a/src/llm/explore.js
+++ b/src/llm/explore.js
@@ -116,9 +116,10 @@ function resolveClass(profile, field) {
  if (!shape) return null;
  const f = shape.fields.find(x => x.name === fieldLabel);
  if (f?.class) return f.class;
-  if (f?.node) {
-    const linked = profile.shapes.find(s => s.uri === f.node);
-    return linked?.targetClass || null;
+  if (f?.nodes.length) {
+    // sh:or of several entities: only when they share one class
+    const classes = new Set(f.nodes.map(n => profile.shapes.find(s => s.uri === n)?.targetClass || null));
+    return classes.size === 1 ? [...classes][0] : null;
  }
  // The model sometimes writes shape.field on a linked shape
  // ("bestuurseenheid.naam"); resolve it to that shape's target class.
--- a/src/runner/check.js
+++ b/src/runner/check.js
@@ -1,4 +1,4 @@
-import { startShape, fieldsOf, field } from './profile.js';
+import { startShape, fieldsOf } from './profile.js';
 import { NUMERIC_DATATYPES } from './assemble.js';
 import { sharedSteps } from './spec.js';

@@ -119,14 +119,10 @@ function collectMinMaxTyped(spec, profile) {
    const name = col.collect === SH + 'min' ? 'sh:min' : 'sh:max';
    if (!col.path.length) return `${name} on a rep:self column does not apply. A subject URI is not a number or date.`;
    const last = col.path[col.path.length - 1];
-    const shapeUri = shapeAfter(profile, startShapeUri, col.path);
-    if (!shapeUri) continue;   // pathsResolve already reported the real error
-    const f = field(profile, shapeUri, last);
-    if (!f) continue;
-    const kind = f.datatype === XSD_DATETIME || f.datatype === XSD_DATE ? 'date'
-      : NUMERIC_DATATYPES.has(f.datatype) ? 'number'
-      : null;
-    if (!kind) {
+    // no end field: pathsResolve already reported the real error
+    const f = endFields(profile, startShapeUri, col.path)
+      .find(x => x.datatype !== XSD_DATETIME && x.datatype !== XSD_DATE && !NUMERIC_DATATYPES.has(x.datatype));
+    if (f) {
      return `"${f.name || last.predicate}" is text, so ${name} does not apply. Use rep:row (same as leaving rep:collect out: every value gets its own row).`;
    }
  }
@@ -291,15 +287,15 @@ function rangeOnValue(spec, profile) {
    const key = ['minInclusive', 'maxInclusive', 'minExclusive', 'maxExclusive']
      .find(k => cond.constraints[k]);
    if (!key || !cond.path.length) continue;
-    const last = cond.path[cond.path.length - 1];
-    const f = field(profile, shapeAfter(profile, startShapeUri, cond.path), last);
-    if (!f || f.datatype) continue;   // pathsResolve reports a missing step
-    const target = f.node
-      ? `"${profile.shapes.find(s => s.uri === f.node)?.label || f.node}"`
+    // pathsResolve reports a missing step
+    const f = endFields(profile, startShapeUri, cond.path).find(x => !x.datatype);
+    if (!f) continue;
+    const target = f.nodes.length
+      ? f.nodes.map(uri => shapeName(profile, uri)).join(' or ')
      : `the code "${f.name}"`;
-    const steps = fieldsOf(profile, f.node)
+    const steps = [...new Set(f.nodes.flatMap(uri => fieldsOf(profile, uri))
      .filter(x => x.datatype === XSD_DATE || x.datatype === XSD_DATETIME || NUMERIC_DATATYPES.has(x.datatype))
-      .map(x => `${x.name} (${x.path})`);
+      .map(x => `${x.name} (${x.path})`))];
    const add = steps.length ? `Add a step: ${steps.join(' or ')}.` : 'End the path on a date or number field.';
    return `${what} ends on ${target}, not on a value, so sh:${key} never matches. ${add}`;
  }
@@ -316,15 +312,18 @@ export function whereNotes(spec, profile) {
  });
 }

-// The entity a path lands on, or the value field when it ends on one.
+// The entity a path lands on, or the value field when it ends on one. A
+// step that leads to several entities names them all.
 function nodeName(profile, startShapeUri, hops) {
-  let shapeUri = startShapeUri;
-  for (const [i, hop] of hops.entries()) {
-    const f = field(profile, shapeUri, hop);
-    if (!f) return `step ${hops.length}`;
-    if (!f.node) return i === hops.length - 1 ? `the value "${f.name}"` : `step ${hops.length}`;
-    shapeUri = f.node;
-  }
+  if (!hops.length) return shapeName(profile, startShapeUri);
+  const ends = endFields(profile, startShapeUri, hops);
+  if (!ends.length) return `step ${hops.length}`;
+  const value = ends.find(f => !f.nodes.length);
+  if (value) return `the value "${value.name}"`;
+  return [...new Set(ends.flatMap(f => f.nodes))].map(uri => shapeName(profile, uri)).join(' or ');
+}
+
+function shapeName(profile, shapeUri) {
  return `"${profile.shapes.find(s => s.uri === shapeUri)?.label || shapeUri}"`;
 }

@@ -367,17 +366,24 @@ export function checkSpec(spec, profiles) {
  return null;
 }

-// The shape a path lands in: follow sh:node through every hop but the
-// last. walk() has already validated the path, so a gap here means the walk
-// reported the real error and this can bail.
-function shapeAfter(profile, startShapeUri, hops) {
-  let shapeUri = startShapeUri;
-  for (let i = 0; i < hops.length - 1; i++) {
-    const f = field(profile, shapeUri, hops[i]);
-    if (!f || !f.node) return null;
-    shapeUri = f.node;
+// The fields a hop takes from any of the shapes a path has reached. A field
+// may link to several entities (sh:or of sh:node: an eenheid's political and
+// leidinggevende organen): the walk follows them all and the next steps
+// decide. The query follows predicates only, so this is what the data does.
+function hopFields(profile, shapeUris, hop) {
+  return shapeUris.flatMap(uri => fieldsOf(profile, uri)
+    .filter(f => f.path === hop.predicate && !!f.inverse === !!hop.inverse));
+}
+
+// The fields a path can end on: follow sh:node through every hop but the
+// last. walk() has already validated the path, so none here means the walk
+// reported the real error and the caller can bail.
+function endFields(profile, startShapeUri, hops) {
+  let shapeUris = [startShapeUri];
+  for (const hop of hops.slice(0, -1)) {
+    shapeUris = [...new Set(hopFields(profile, shapeUris, hop).flatMap(f => f.nodes))];
  }
-  return shapeUri;
+  return hopFields(profile, shapeUris, hops[hops.length - 1]);
 }

 function walk(profile, startShapeUri, hops, what, isColumn, wantsIri = false) {
@@ -385,32 +391,36 @@ function walk(profile, startShapeUri, hops, what, isColumn, wantsIri = false) {
    return `${what} walks ${hops.length} hops. The limit is ${MAX_PATH_DEPTH}.`;
  }
  if (!hops.length) return null;
-  let shapeUri = startShapeUri;
+  let shapeUris = [startShapeUri];
  for (let i = 0; i < hops.length; i++) {
    const hop = hops[i];
-    const fields = fieldsOf(profile, shapeUri);
-    const f = fields.find(x => x.path === hop.predicate && !!x.inverse === !!hop.inverse);
-    if (!f) {
-      const have = fields.map(x => (x.inverse ? `${x.name} (${x.path}, inverse)` : `${x.name} (${x.path})`)).join(', ');
-      const shapeLabel = profile.shapes.find(s => s.uri === shapeUri)?.label || shapeUri;
-      return `at "${shapeLabel}" there is no "${hop.predicate}". It has: ${have || '(nothing)'}.`;
+    const found = hopFields(profile, shapeUris, hop);
+    if (!found.length) {
+      const have = [...new Set(shapeUris.flatMap(uri => fieldsOf(profile, uri))
+        .map(x => (x.inverse ? `${x.name} (${x.path}, inverse)` : `${x.name} (${x.path})`)))].join(', ');
+      const shapeLabel = shapeUris.map(uri => shapeName(profile, uri)).join(' or ');
+      return `at ${shapeLabel} there is no "${hop.predicate}". It has: ${have || '(nothing)'}.`;
    }
    if (i < hops.length - 1) {
-      if (!f.node) {
+      const links = found.filter(f => f.nodes.length);
+      if (!links.length) {
        return `${what} hop ${i + 1} <${hop.predicate}> holds a value, not a link. You cannot walk past it.`;
      }
-      shapeUri = f.node;
+      shapeUris = [...new Set(links.flatMap(f => f.nodes))];
    } else if (isColumn) {
+      // every field the path can end on must suit the column
+      for (const f of found) {
        if (wantsIri && f.datatype) {
          return `${what} has sh:nodeKind sh:IRI but ends on the value "${f.name}", which is no URI. Drop sh:nodeKind.`;
        }
        if (!wantsIri && !f.datatype && !f.class) {
-        const valueFields = fieldsOf(profile, f.node)
+          const valueFields = [...new Set(f.nodes.flatMap(uri => fieldsOf(profile, uri))
            .filter(x => x.datatype || x.class)
-          .map(x => `${x.name} (${x.path})`);
+            .map(x => `${x.name} (${x.path})`))];
          return `${what} ends on a link. Add a hop: ${valueFields.join(' or ')}. Only if the user asked for the URI of that node itself, add sh:nodeKind sh:IRI to the column instead.`;
        }
      }
    }
+  }
  return null;
 }
--- a/src/runner/profile.js
+++ b/src/runner/profile.js
@@ -1,5 +1,6 @@
 import N3 from 'n3';
 import { readFileSync, readdirSync } from 'fs';
+import { parseFilter, readRdfList } from './spec.js';

 // Parse a profile (a SHACL shapes graph) and answer questions about it.

@@ -41,8 +42,8 @@ function loadProfile(file) {
    const targetClass = store.getQuads(shape, SH + 'targetClass', null)[0]?.object.value || null;
    const label = store.getQuads(shape, 'http://www.w3.org/2000/01/rdf-schema#label', null)[0]?.object.value || null;
    const fields = store.getQuads(shape, SH + 'property', null).map(q => parseField(store, q.object));
-    const discriminator = parseDiscriminator(store, shape);
-    return { uri: shape.value, targetClass, label, fields, discriminator };
+    const discriminators = parseDiscriminators(store, shape);
+    return { uri: shape.value, targetClass, label, fields, discriminators };
  });

  return { uri, title, shapes: shapeList };
@@ -64,25 +65,49 @@ function parseField(store, p) {
    name: one(SH + 'name'),
    datatype: one(SH + 'datatype'),
    class: one(SH + 'class'),
-    node: one(SH + 'node'),
+    nodes: linkedShapes(store, p, one(SH + 'name')),
  };
 }

-// rep:discriminator tells shapes that share a targetClass apart. sh:minCount 1
-// becomes a plain triple in the seed, sh:maxCount 0 a FILTER NOT EXISTS.
-function parseDiscriminator(store, shape) {
-  const node = store.getQuads(shape, REP + 'discriminator', null)[0]?.object;
-  if (!node) return null;
-  const { path, inverse } = readPath(store, node);
-  const one = (pred) => store.getQuads(node, pred, null)[0]?.object?.value || null;
-  const minCount = one(SH + 'minCount');
-  const maxCount = one(SH + 'maxCount');
-  if (!path || (minCount === null && maxCount === null)) return null;
-  return {
-    path, inverse,
-    minCount: minCount !== null ? Number(minCount) : null,
-    maxCount: maxCount !== null ? Number(maxCount) : null,
+// The entities a field links to: its sh:node, or the sh:node of each item of
+// its sh:or (SHACL for "each value is one of these").
+function linkedShapes(store, p, name) {
+  const node = store.getQuads(p, SH + 'node', null)[0]?.object;
+  if (node) return [node.value];
+  const or = store.getQuads(p, SH + 'or', null)[0]?.object;
+  if (!or) return [];
+  return readRdfList(store, or).map(item => {
+    const n = store.getQuads(item, SH + 'node', null)[0]?.object;
+    if (!n) throw new Error(`field "${name}": every sh:or item needs a sh:node.`);
+    return n.value;
+  });
+}
+
+// rep:discriminator tells shapes that share a targetClass apart. A shape may
+// carry several; a subject meets them all.
+function parseDiscriminators(store, shape) {
+  return store.getQuads(shape, REP + 'discriminator', null)
+    .map(q => parseDiscriminator(store, q.object, shape.value));
+}
+
+// One discriminator: a condition written like a spec filter (sh:path plus
+// sh:minCount, sh:maxCount, sh:in, sh:hasValue, ...), or sh:and / sh:or (a
+// list) or sh:not (one) over discriminators, as in SHACL.
+function parseDiscriminator(store, node, shapeUri) {
+  const one = (pred) => store.getQuads(node, SH + pred, null)[0]?.object;
+  const list = (pred) => {
+    const items = readRdfList(store, one(pred)).map(x => parseDiscriminator(store, x, shapeUri));
+    if (!items.length) throw new Error(`rep:discriminator on <${shapeUri}> has an empty sh:${pred}.`);
+    return items;
  };
+  if (one('and')) return { and: list('and') };
+  if (one('or')) return { or: list('or') };
+  if (one('not')) return { not: parseDiscriminator(store, one('not'), shapeUri) };
+  const d = parseFilter(store, node);
+  if (!d.path.length || !Object.keys(d.constraints).length) {
+    throw new Error(`rep:discriminator on <${shapeUri}> needs a sh:path with a condition, or sh:and, sh:or or sh:not.`);
+  }
+  return d;
 }

 // The shape a spec starts from. rep:entity wins; a targetClass only resolves
@@ -101,8 +126,3 @@ export function shape(profile, shapeUri) {
 export function fieldsOf(profile, shapeUri) {
  return shape(profile, shapeUri)?.fields || [];
 }
-
-// The field a hop takes from a shape, or null.
-export function field(profile, shapeUri, hop) {
-  return fieldsOf(profile, shapeUri).find(f => f.path === hop.predicate && !!f.inverse === !!hop.inverse) || null;
-}
--- a/src/runner/seed.js
+++ b/src/runner/seed.js
@@ -25,7 +25,9 @@ export function seedPageQuery(spec, limit, offset, shape = null) {
  const parts = [];
  const targetClass = spec.targetClass || shape?.targetClass;
  parts.push(`?s a ${sparqlEscapeUri(targetClass)} .`);
-  if (shape?.discriminator) parts.push(discriminatorPattern(shape.discriminator));
+  (shape?.discriminators || []).forEach((d, di) => {
+    parts.push(discriminatorPattern(d, `disc${di}`));
+  });
  spec.filters.forEach((filter, fi) => {
    parts.push(filterPattern(filter, `f${fi}`));
  });
@@ -36,13 +38,20 @@ LIMIT ${limit} OFFSET ${offset}`;
 }

 // A shape that shares its class with another says here what sets its
-// subjects apart: sh:minCount 1 is a plain triple, sh:maxCount 0 a NOT EXISTS.
-function discriminatorPattern(d) {
-  const p = sparqlEscapeUri(d.path);
-  const triple = d.inverse ? `?disc ${p} ?s .` : `?s ${p} ?disc .`;
-  if (d.minCount !== null && d.minCount >= 1) return triple;
-  if (d.maxCount === 0) return `FILTER NOT EXISTS { ${triple} }`;
-  return null;
+// subjects apart. A plain discriminator is a filter; sh:and, sh:or and sh:not
+// become one FILTER over EXISTS tests, which see ?s from outside.
+function discriminatorPattern(d, varPrefix) {
+  if (!d.and && !d.or && !d.not) return filterPattern(d, varPrefix);
+  return `FILTER(${discriminatorTest(d, varPrefix)})`;
+}
+
+function discriminatorTest(d, varPrefix) {
+  if (d.and) return `(${d.and.map((x, i) => discriminatorTest(x, `${varPrefix}_${i}`)).join(' && ')})`;
+  if (d.or) return `(${d.or.map((x, i) => discriminatorTest(x, `${varPrefix}_${i}`)).join(' || ')})`;
+  if (d.not) return `!(${discriminatorTest(d.not, `${varPrefix}_n`)})`;
+  const { maxCount, ...test } = d.constraints;
+  if (maxCount === 0) return `NOT EXISTS { ${filterPattern({ ...d, constraints: test }, varPrefix)} }`;
+  return `EXISTS { ${filterPattern(d, varPrefix)} }`;
 }

 // Writes out every hop as its own triple pattern.
@@ -66,13 +75,15 @@ export function hopsPattern(hops, varPrefix, startVar, lastVar = `?${varPrefix}_
 }

 // One filter: its condition, plus its rep:where conditions on the nodes it
-// walks through. With sh:maxCount 0 the whole of it becomes "none such".
+// walks through. With sh:maxCount 0 the whole of it becomes "none such";
+// with a value test too (sh:in, sh:hasValue, ...), "none with such a value".
 function filterPattern(filter, varPrefix) {
+  const { maxCount, ...test } = filter.constraints;
+  if (maxCount === 0) {
+    return `FILTER NOT EXISTS {\n    ${filterPattern({ ...filter, constraints: test }, varPrefix)}\n  }`;
+  }
  const nodeVar = (k) => (k === filter.path.length ? `?${varPrefix}_v` : `?${varPrefix}_${k}`);
  const wheres = wherePatterns(filter.where, filter.path, nodeVar, varPrefix);
-  if (filter.constraints.maxCount === 0) {
-    return `FILTER NOT EXISTS {\n    ${[hopsPattern(filter.path, varPrefix, '?s'), ...wheres].join('\n    ')}\n  }`;
-  }
  return [conditionPattern(filter.constraints, varPrefix, filter.path, '?s'), ...wheres].join('\n  ');
 }

@@ -89,10 +100,11 @@ export function wherePatterns(where, hostHops, nodeVar, varPrefix) {
 // A condition: the hops from startVar and the test on where they end. A
 // filter starts at ?s; a rep:where starts at a node of its host and, with no
 // hops left, tests that node itself. sh:maxCount 0 means "none such", so its
-// hops only live inside the NOT EXISTS.
+// hops and any value test only live inside the NOT EXISTS.
 export function conditionPattern(c, varPrefix, hops, startVar) {
  if (c.maxCount === 0) {
-    return `FILTER NOT EXISTS { ${hopsPattern(hops, varPrefix + '_nex', startVar)} }`;
+    const { maxCount, ...test } = c;
+    return `FILTER NOT EXISTS { ${conditionPattern(test, varPrefix + '_nex', hops, startVar)} }`;
  }
  const v = hops.length ? `?${varPrefix}_v` : startVar;
  const parts = hops.length ? [hopsPattern(hops, varPrefix, startVar)] : [];
--- a/src/runner/spec.js
+++ b/src/runner/spec.js
@@ -31,7 +31,7 @@ export function parseSpec(turtle) {
  return { uri: specNode.value, title, profileUri, targetClass, entity, filters, columns };
 }

-function parseFilter(store, p) {
+export function parseFilter(store, p) {
  let path = [];
  const pathQuad = store.getQuads(p, SH + 'path', null)[0]?.object;
  if (pathQuad) path = parsePath(store, pathQuad);
@@ -134,7 +134,7 @@ function readConstraints(store, p, { withLabel = false } = {}) {
  return constraints;
 }

-function readRdfList(store, node) {
+export function readRdfList(store, node) {
  const items = [];
  let cur = node;
  while (cur && cur.value !== RDF + 'nil') {