stanfordnlp/CoreNLP · error · ParseException

Relation does not allow for named edges

Error message

Relation  does not allow for named edges

What it means

This ParseException is thrown by GraphRelation.getRelation(String,String,String,String) in Stanford Semgrex when a named edge (edgeName, the ':name' clause of a relation) is attached to a relation that does not support edge naming. Only directional relations ('>', '<', '>++', '>--', '<++', '<--', '<>') construct relation objects that accept an edgeName; all others (grandparent, sibling, adjacency, alignment, equality) reject it. The message includes the offending relation symbol.

Solutions

1. Remove the ':edgeName' suffix from the relation in the pattern (e.g. '<<:dep' -> '<<').
2. Use a relation that supports named edges: '>', '<', '<>', '>++', '>--', '<++', '<--'.
3. If you call getRelation directly, pass null for edgeName for non-directional relations.
4. Check GraphRelation.isKnownRelation and the first switch in getRelation to confirm which relations accept edgeName before attaching one.

Example fix

// before
GraphRelation r = GraphRelation.getRelation("<<", null, name, "dep"); // throws
// after
GraphRelation r = GraphRelation.getRelation("<<", null, name, null); // or use ">" with "dep"

boolean supportsNamedEdge(String reln) {
  return reln.equals(">") || reln.equals("<") || reln.equals("<>")
      || reln.equals(">++") || reln.equals(">--")
      || reln.equals("<++") || reln.equals("<--");
}
// before calling: if (!supportsNamedEdge(reln)) edgeName = null;

if (edgeName != null && !supportsNamedEdge(reln)) {
  throw new IllegalArgumentException("Relation " + reln + " does not support named edges");
}

try {
  GraphRelation r = GraphRelation.getRelation(reln, type, name, edgeName);
} catch (ParseException e) {
  if (e.getMessage().contains("does not allow for named edges")) {
    r = GraphRelation.getRelation(reln, type, name, null);
  }
}

When it happens

Trigger: Calling getRelation(reln, type, name, edgeName) with a non-null edgeName for a relation not in the first switch block, e.g. getRelation("<<", null, name, "myedge") or getRelation("$+", null, name, "e"). Parsing a Semgrex pattern like '<<:dep' or '.:x' where the named-edge syntax is applied to an unsupported operator.

Common situations: Hand-written Semgrex patterns where the user assumes every operator supports ':edgeName' annotation; programmatically built patterns in annotator pipelines that append edge names uniformly to all relations; migrating patterns between Semgrex versions where the set of named-edge-capable relations differs.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• Relation not handled by getRelation
• Relation does not use numeric arguments
• Unrecognized compound relation
• Invalid txtGraph
• Invalid hypGraph

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/578fdbee71b6a9b9. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/semgraph/semgrex/GraphRelation.java:1479

    }
    switch (reln) {
      case ">":
        return new GOVERNOR(type, name, edgeName);
      case ">++":
        return new GOVERNOR_RIGHT(type, name, edgeName);
      case ">--":
        return new GOVERNOR_LEFT(type, name, edgeName);
      case "<":
        return new DEPENDENT(type, name, edgeName);
      case "<++":
        return new DEPENDENT_RIGHT(type, name, edgeName);
      case "<--":
        return new DEPENDENT_LEFT(type, name, edgeName);
      case "<>":
        return new CONNECTED(type, name, edgeName);
    }
    if (edgeName != null) {
      throw new ParseException("Relation " + reln + " does not allow for named edges");
    }
    switch (reln) {
      case ">>":
        return new GRANDPARENT(type, name);
      case "<<":
        return new GRANDKID(type, name);
      case "==":
        return new EQUALS(type, name);
      case "$+":
        return new RIGHT_IMMEDIATE_SIBLING(type, name);
      case "$-":
        return new LEFT_IMMEDIATE_SIBLING(type, name);
      case "$++":
        return new RIGHT_SIBLING(type, name);
      case "$--":
        return new LEFT_SIBLING(type, name);
      case ".":
        return new ADJACENT_RIGHT(type, name);

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