Label language preferences + diff-pretty label-language prefs support

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Add `--label-langs-priority` option to `diff` for choosing entity labels by language preference in the `pretty` format
+
 ### Fixed
 
 - Fix problem with catalog file for compressed ontologies [#1281]

docs/diff.md

@@ -32,6 +32,29 @@ See [release-diff.txt](/examples/release-diff.txt) for an example.
 
 The default "plain" output is in OWL Functional syntax with IRIs. You can include entity labels with `--labels true`. In addition, Markdown and HTML diff formats (based on Manchester syntax) are available. You can select the desired format using the `--format` (or `-f`) option, with possible values `plain`, `pretty` (text with labels and CURIEs), `html`, or `markdown`.
 
+### Label Languages
+
+When an entity has labels in more than one language, you can control which one is shown in the `pretty` format with `--label-langs-priority`, a comma-separated list of [language tags](https://www.rfc-editor.org/info/bcp47) in priority order:
+
+    robot diff --left lang-left.owl \
+      --right lang-right.owl \
+      --format pretty \
+      --label-langs-priority en-GB,en \
+      --output results/lang-diff.txt
+
+Here the `dog` class carries `de`, `en`, and `en-GB` labels; with `en-GB,en` its British label `hound` is chosen. Selection rules:
+
+- A more general tag matches a more specific one — for example, `en` matches a label tagged `en-GB`. Each label is bound to the *most specific* tag in your list that it matches, and the label bound to the *earliest* listed tag wins.
+- Listing a specific tag after a general one deprioritizes it. With `en,en-GB`, a label tagged `en-GB` binds to `en-GB` (position 2), while a label tagged `en-US` binds to `en` (position 1, by cascade) — so the `en-US` label is shown. To prefer British labels instead, list `en-GB` first.
+- Use the token `none` to prefer labels that have no language tag (for example, `--label-langs-priority en,none`).
+- Use `*` as a catch-all that matches any label (for example, `--label-langs-priority en,*` prefers English but falls back to any available label). `*` is the least specific match, so any listed language is preferred over it.
+- When more than one label is bound to the winning tag (for example, two labels tagged `en`), the alphabetically first is chosen.
+- If an entity has labels but none in a preferred language, its alphabetically first label is used, so a labelled entity is never shown as its IRI. Entities with no label at all are unaffected.
+
+Tag matching follows [RFC 4647](https://www.rfc-editor.org/rfc/rfc4647.html) Basic Filtering (a tag like `en` matches any label tagged `en` or beginning `en-`, and `*` matches anything); ROBOT then uses your list's priority order and the tie-breaks above to choose a single label.
+
+This option currently applies only to the `pretty` format; the `markdown` and `html` formats are not yet affected.
+
 You can also compare ontologies by IRI with `--left-iri` and `--right-iri`. You may want to compare a local file to a release, in which case:
 <!-- DO NOT TEST -->
 ```

docs/examples/lang-diff.txt

@@ -0,0 +1,6 @@
+2 axioms in left ontology but not in right ontology:
+- OntologyID(OntologyIRI(<https://github.com/ontodev/robot/examples/lang-left.owl>) VersionIRI(<null>))
+- SubClassOf(<https://github.com/ontodev/robot/examples/lang.owl#puppy> <https://github.com/ontodev/robot/examples/lang.owl#dog>[hound])
+
+1 axioms in right ontology but not in left ontology:
++ OntologyID(OntologyIRI(<https://github.com/ontodev/robot/examples/lang-right.owl>) VersionIRI(<null>))

docs/examples/lang-left.owl

@@ -0,0 +1,20 @@
+<?xml version="1.0"?>
+<rdf:RDF xmlns="https://github.com/ontodev/robot/examples/lang.owl#"
+     xml:base="https://github.com/ontodev/robot/examples/lang.owl"
+     xmlns:owl="http://www.w3.org/2002/07/owl#"
+     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+     xmlns:xml="http://www.w3.org/XML/1998/namespace"
+     xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
+     xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">
+    <owl:Ontology rdf:about="https://github.com/ontodev/robot/examples/lang-left.owl"/>
+
+    <owl:Class rdf:about="https://github.com/ontodev/robot/examples/lang.owl#dog">
+        <rdfs:label xml:lang="de">Hund</rdfs:label>
+        <rdfs:label xml:lang="en">dog</rdfs:label>
+        <rdfs:label xml:lang="en-GB">hound</rdfs:label>
+    </owl:Class>
+
+    <owl:Class rdf:about="https://github.com/ontodev/robot/examples/lang.owl#puppy">
+        <rdfs:subClassOf rdf:resource="https://github.com/ontodev/robot/examples/lang.owl#dog"/>
+    </owl:Class>
+</rdf:RDF>

docs/examples/lang-right.owl

@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<rdf:RDF xmlns="https://github.com/ontodev/robot/examples/lang.owl#"
+     xml:base="https://github.com/ontodev/robot/examples/lang.owl"
+     xmlns:owl="http://www.w3.org/2002/07/owl#"
+     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+     xmlns:xml="http://www.w3.org/XML/1998/namespace"
+     xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
+     xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">
+    <owl:Ontology rdf:about="https://github.com/ontodev/robot/examples/lang-right.owl"/>
+
+    <owl:Class rdf:about="https://github.com/ontodev/robot/examples/lang.owl#dog">
+        <rdfs:label xml:lang="de">Hund</rdfs:label>
+        <rdfs:label xml:lang="en">dog</rdfs:label>
+        <rdfs:label xml:lang="en-GB">hound</rdfs:label>
+    </owl:Class>
+
+    <owl:Class rdf:about="https://github.com/ontodev/robot/examples/lang.owl#puppy"/>
+</rdf:RDF>

robot-command/src/main/java/org/obolibrary/robot/DiffCommand.java

@@ -53,6 +53,16 @@ public DiffCommand() {
         null, "labels", true, "if true, append labels after entity IRIs in the text format output");
     o.addOption(
         "f", "format", true, "format for diff output: plain (default) | pretty | html | markdown");
+    o.addOption(
+        null,
+        LanguagePreference.OPTION_NAME,
+        true,
+        "comma-separated language tags, in priority order, for choosing entity labels in the"
+            + " 'pretty' format (e.g. 'en-GB,en,"
+            + LanguagePreference.NO_LANG_TOKEN
+            + "'); use '"
+            + LanguagePreference.NO_LANG_TOKEN
+            + "' for values with no language tag");
     options = o;
   }
 
@@ -159,6 +169,11 @@ public CommandState execute(CommandState state, String[] args) throws Exception
     Map<String, String> options = new HashMap<>();
     options.put("labels", CommandLineHelper.getDefaultValue(line, "labels", "false"));
     options.put("format", CommandLineHelper.getDefaultValue(line, "format", "plain"));
+    String preferredLangs =
+        CommandLineHelper.getOptionalValue(line, LanguagePreference.OPTION_NAME);
+    if (preferredLangs != null) {
+      options.put(LanguagePreference.OPTION_NAME, preferredLangs);
+    }
 
     DiffOperation.compare(leftOntology, rightOntology, ioHelper, writer, options);
     writer.close();

robot-core/src/main/java/org/obolibrary/robot/DiffOperation.java

@@ -13,10 +13,12 @@
 import org.geneontology.owl.differ.render.MarkdownGroupedDiffRenderer;
 import org.geneontology.owl.differ.shortform.DoubleShortFormProvider;
 import org.geneontology.owl.differ.shortform.OBOShortenerShortFormProvider;
+import org.obolibrary.robot.providers.PreferredLanguageShortFormProvider;
 import org.semanticweb.owlapi.apibinding.OWLManager;
 import org.semanticweb.owlapi.model.*;
 import org.semanticweb.owlapi.util.AnnotationValueShortFormProvider;
 import org.semanticweb.owlapi.util.DefaultPrefixManager;
+import org.semanticweb.owlapi.util.ShortFormProvider;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -104,6 +106,18 @@ public static boolean compare(
       format = "pretty";
     }
 
+    // An ordered list of preferred label languages (empty means "no preference").
+    List<String> preferredLangs =
+        LanguagePreference.parse(OptionsHelper.getOption(options, LanguagePreference.OPTION_NAME));
+    if (!preferredLangs.isEmpty() && !format.equals("pretty")) {
+      // Only the "pretty" format currently supports language-prioritized labels; the markdown and
+      // html renderers build their own label provider inside the owl-diff library.
+      logger.warn(
+          "The --{} option only affects the 'pretty' diff format; it is ignored for format '{}'.",
+          LanguagePreference.OPTION_NAME,
+          format);
+    }
+
     Differ.BasicDiff diff = Differ.diff(ontology1, ontology2);
 
     if (diff.isEmpty()) {
@@ -127,13 +141,19 @@ public static boolean compare(
         break;
       case "pretty":
         DefaultPrefixManager pm = ioHelper.getPrefixManager();
-        AnnotationValueShortFormProvider labelProvider =
-            new AnnotationValueShortFormProvider(
-                ontologyProvider,
-                pm,
-                pm,
-                Collections.singletonList(OWLManager.getOWLDataFactory().getRDFSLabel()),
-                Collections.emptyMap());
+        List<OWLAnnotationProperty> labelProperties =
+            Collections.singletonList(OWLManager.getOWLDataFactory().getRDFSLabel());
+        ShortFormProvider labelProvider;
+        if (preferredLangs.isEmpty()) {
+          // No language preference: keep the pre-existing behavior exactly.
+          labelProvider =
+              new AnnotationValueShortFormProvider(
+                  ontologyProvider, pm, pm, labelProperties, Collections.emptyMap());
+        } else {
+          labelProvider =
+              new PreferredLanguageShortFormProvider(
+                  ontologyProvider, labelProperties, preferredLangs, pm);
+        }
         OBOShortenerShortFormProvider iriProvider = new OBOShortenerShortFormProvider(pm);
         DoubleShortFormProvider doubleProvider =
             new DoubleShortFormProvider(iriProvider, labelProvider);