stanfordnlp/CoreNLP · error · RuntimeException

%s: Term lacks morpho analysis: %s

Error message

%s: Term lacks morpho analysis: %s

What it means

When the Arabic treebank params apply tag-level morphosyntactic features, it requires each pre-terminal's leaf label to be a CoreLabel carrying a non-null originalText() that encodes the morphological analysis (tag Spec). If the label is not a CoreLabel or originalText() is null, the tree lacks the morpho analysis the tagSpec expects, so a RuntimeException with the class name and tree is thrown.

Solutions

  1. Load trees with the Arabic-specific tree reader factory that produces CoreLabels with originalText set to the morphological analysis
  2. Verify the input treebank lines contain the morpho analyses (the tab-separated analyses field)
  3. Disable the morphological-feature option if your trees have no morpho analysis

Example fix

// before
TreeReaderFactory trf = new LabeledScoredTreeReaderFactory();
// after (use the Arabic params' default reader)
TreeReaderFactory trf = params.treeReaderFactory(); // ArabicTreebankParserParams -> ArabicTreeReaderFactory with morpho analyses
Defensive patterns

Strategy: validation

Validate before calling

// before transformTree, check each pre-terminal leaf
for (Tree t : tree.preTerminals()) {
  if (!(t.firstChild().label() instanceof CoreLabel)
      || ((CoreLabel) t.firstChild().label()).originalText() == null) {
    throw new IllegalArgumentException("Tree lacks morpho analysis at: " + t);
  }
}

Type guard

function hasMorphoAnalysis(t) {
  return t.isPreTerminal() && t.firstChild().label() instanceof CoreLabel
      && ((CoreLabel) t.firstChild().label()).originalText() != null;
}

Try / catch

try {
  Tree transformed = params.transformTree(t);
} catch (RuntimeException e) {
  if (e.getMessage().contains("Term lacks morpho analysis")) {
    log.severe("Input trees missing Arabic morpho analyses; reload with Arabic tree reader");
  }
  throw e;
}

Prevention

When it happens

Trigger: Parsing/transforming Arabic trees with morphological tagging enabled (uncaught tagSpec) while the input trees were read with default LabeledScoredTreeReaderFactory so leaves are not CoreLabels, or the reader did not set originalText from the gold morpho analysis column.

Common situations: Training/evaluating the Arabic parser where tree files were loaded without the Arabic custom tree reader that parses the morphological analyses; using tree output from another tool that strips the 'morpho' annotation.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/cddcbfbfa17661a5. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/parser/lexparser/ArabicTreebankParserParams.java:250

  
  @Override
  public Tree transformTree(Tree t, Tree root) {

    String baseCat = t.value();
    StringBuilder newCategory = new StringBuilder();

    //Add manual state splits
    for (Pair<TregexPattern,Function<TregexMatcher,String>> e : activeAnnotations) {
      TregexMatcher m = e.first().matcher(root);
      if (m.matchesAt(t))
        newCategory.append(e.second().apply(m));
    }

    // WSGDEBUG
    //Add morphosyntactic features if this is a POS tag
    if(t.isPreTerminal() && tagSpec != null) {
      if( !(t.firstChild().label() instanceof CoreLabel) || ((CoreLabel) t.firstChild().label()).originalText() == null )
        throw new RuntimeException(String.format("%s: Term lacks morpho analysis: %s",this.getClass().getName(),t.toString()));

      String morphoStr = ((CoreLabel) t.firstChild().label()).originalText();
      MorphoFeatures feats = tagSpec.strToFeatures(morphoStr);
      baseCat = feats.getTag(baseCat);
    }

    //Update the label(s)
    String newCat = baseCat + newCategory;
    t.setValue(newCat);
    if (t.isPreTerminal() && t.label() instanceof HasTag)
      ((HasTag) t.label()).setTag(newCat);

    return t;
  }

  /**
   * These are the annotations included when the user selects the -arabicFactored option.
   */

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