stanfordnlp/CoreNLP · error · SsurgeonParseException

ReattachNamedEdge created with no edge name!

Error message

ReattachNamedEdge created with no edge name!

What it means

ReattachNamedEdge reattaches an edge that was matched and named in the SemgrexPattern to a new governor and/or dependent. It requires the name of that matched edge; if the edgeName argument is null it cannot know which edge to operate on and throws immediately in the constructor.

Solutions

  1. Pass the name of the edge as it is named in the SemgrexPattern (the edge: marker name) as the first argument
  2. Check the Ssurgeon resource line: ensure the reattach-named-edge operation lists the named edge argument before gov/dep
  3. Verify the corresponding SemgrexPattern actually names an edge with that name (edge= clause)

Example fix

// before
new ReattachNamedEdge(null, "gov", "dep");
// after
new ReattachNamedEdge("myEdge", "gov", "dep"); // 'myEdge' matches edge= in the SemgrexPattern
Defensive patterns

Strategy: validation

Validate before calling

if (edgeName == null || edgeName.isEmpty()) {
  throw new IllegalArgumentException("reattach-named-edge requires the name of an edge matched in the SemgrexPattern");
}

Type guard

boolean hasEdgeName(String name) { return name != null && !name.isEmpty(); }

Try / catch

try {
  op = new ReattachNamedEdge(edgeName, gov, dep);
} catch (SsurgeonParseException e) {
  log.error("Bad Ssurgeon rule: {}", e.getMessage());
  throw new RuleSyntaxException(e);
}

Prevention

When it happens

Trigger: Calling new ReattachNamedEdge(null, gov, dep) directly, or an Ssurgeon resource line 'reattach-named-edge' whose first argument (the named edge) is missing or empty.

Common situations: Hand-editing an Ssurgeon rule file and deleting the edge name token; building the operation programmatically where the edge name variable was never assigned; a malformed resource line parsed with a missing field.

Related errors

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/060f063c4c4844ba. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/semgraph/semgrex/ssurgeon/ReattachNamedEdge.java:29

 * Given a named edge, reconnect that edge elsewhere in the graph, changing either the gov and/or dep.
 *<br>
 * If an edge already exists with the new named relation,
 * <i>that</i> edge is deleted permanently.  That way, named
 * references to the first edge should still work.
 *
 * @author John Bauer
 *
 */
public class ReattachNamedEdge extends SsurgeonEdit {
  public static final String LABEL = "reattachNamedEdge";

  protected final String edgeName; // Name of the matched edge in the SemgrexPattern
  protected final String govNodeName; // Where to put the new gov.  If null, will not edit
  protected final String depNodeName; // Where to put the new dep.  If null, will not edit

  public ReattachNamedEdge(String edgeName, String gov, String dep) {
    if (edgeName == null) {
      throw new SsurgeonParseException("ReattachNamedEdge created with no edge name!");
    }
    if (gov == null && dep == null) {
      throw new SsurgeonParseException("ReattachNamedEdge created with both gov and dep missing!");
    }

    this.edgeName = edgeName;
    this.govNodeName = gov;
    this.depNodeName = dep;
  }

  @Override
  public String toEditString() {
    StringWriter buf = new StringWriter();
    buf.write(LABEL); buf.write("\t");

    buf.write(Ssurgeon.EDGE_NAME_ARG);buf.write(" ");
    buf.write(edgeName);

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