stanfordnlp/CoreNLP · error · IllegalArgumentException

Coreference is not implemented for Spanish

Error message

Coreference is not implemented for Spanish

What it means

SpanishDocument.coref is an explicit stub: coreference resolution is not implemented for the Spanish simple-API pipeline, so it throws IllegalArgumentException. This signals the unsupported feature at call time instead of silently returning empty results.

Solutions

1. Skip coreference resolution for Spanish documents
2. Use a tool with Spanish coreference support (e.g. cross-lingual coref libraries) outside the simple API
3. Guard the call with a language capability check
4. Handle the IllegalArgumentException explicitly to degrade gracefully

Example fix

// before
Document d = new SpanishDocument(text);
Map<Integer, CorefChain> chains = d.coref(); // throws
// after
if (!(d instanceof SpanishDocument)) {
  Map<Integer, CorefChain> chains = d.coref();
}

if (doc instanceof SpanishDocument) { /* skip coref */ }

boolean supportsCoref(Document d) { return !(d instanceof SpanishDocument); }

try {
  Map<Integer, CorefChain> chains = doc.coref();
} catch (IllegalArgumentException e) {
  chains = Collections.emptyMap();
}

When it happens

Trigger: Calling coref(props) or document.coref() on a SpanishDocument instance.

Common situations: Pipeline code that runs coreference on every document regardless of language; porting English coref workflows to Spanish; downstream components (e.g. entity linking) that depend on CorefChain output.

Related errors

• Sentiment analysis is not implemented for Spanish
• Dependency parsing is not implemented for Spanish
• this.getClass().getName() + ": Case is presently…
• French does not support feature type:
• We don't support disambiguating pronoun

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/b13cfbb430afd06d. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/simple/SpanishDocument.java:95

    return mockLemma(props);
  }


  @Override
  protected Document runSentiment(Properties props) {
    throw new IllegalArgumentException("Sentiment analysis is not implemented for Spanish");
  }


  @Override
  protected Document runDepparse(Properties props) {
    throw new IllegalArgumentException("Dependency parsing is not implemented for Spanish");
  }


  @Override
  public Map<Integer, CorefChain> coref(Properties props) {
    throw new IllegalArgumentException("Coreference is not implemented for Spanish");
  }

}

View on GitHub (pinned to 1b7edd19c4)