stanfordnlp/CoreNLP · error · SsurgeonParseException

SplitWord got a -name parameter which did not have a number…

Error message

SplitWord got a -name parameter which did not have a number for one of the names.  Should look like 0=foo,1=bar

What it means

The optional -name argument of SplitWord assigns semgrex node names to split pieces using the format index=name, comma-separated (e.g. 0=foo,1=bar). Each entry must contain a '=' with a numeric index on the left; otherwise the constructor throws SsurgeonParseException telling you the expected format.

Solutions

Rewrite the -name argument so every entry is index=name with a 0-based integer index, e.g. -name 0=first,1=second
Remove trailing commas or empty entries from the nodeNames string
Validate the string in your tooling with a regex like ^\d+=.+(,\d+=.+)*$ before constructing SplitWord
Also ensure indices are < nodePieces.size(), which is the next check after this one

Example fix

// before
new SplitWord("w", pieces, 0, reln, "foo,1=bar", true);
// after
new SplitWord("w", pieces, 0, reln, "0=foo,1=bar", true);

Defensive patterns

Strategy: validation

Validate before calling

if (nodeNames != null && !nodeNames.matches("\\d+=.+(,\\d+=.+)*")) throw new IllegalArgumentException("-name must look like 0=foo,1=bar");

Try / catch

try { SplitWord sw = new SplitWord(node, pieces, headIndex, reln, names, exact); } catch (SsurgeonParseException e) { log.error("Bad -name format: " + e.getMessage()); }

Prevention

Use the exact index=name, comma-separated format for -name
Strip whitespace and trailing commas from the names string
Validate -name against ^\d+=.+(,\d+=.+)*$ before construction and check indices < pieces.size()

When it happens

Trigger: Passing a nodeNames string where any comma-separated entry lacks a '=' or has no numeric index before it, e.g. -name foo,1=bar or -name 0foo.

Common situations: Typo in the -name argument (missing '=' or space instead of '='); copy-pasting a name list from another rule with a different format; an extra empty entry from a trailing comma producing a piece without '='.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/da1e1fe49367b4ec. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/semgraph/semgrex/ssurgeon/SplitWord.java:87

    }

    if (headIndex == null) {
      throw new SsurgeonParseException("SplitWord expected a -headIndex, 0-indexed for the word piece to use when chopping up the word");
    }
    this.headIndex = headIndex;

    if (relation == null) {
      throw new SsurgeonParseException("SplitWord expected a -reln to represent the dependency to use for the new words");
    }
    this.relation = relation;

    if (nodeNames != null) {
      String[] namePieces = nodeNames.split(",");
      this.nodeNames = new HashMap<>();
      for (String namePiece : namePieces) {
        String[] pieces = namePiece.split("=", 2);
        if (pieces.length < 2) {
          throw new SsurgeonParseException("SplitWord got a -name parameter which did not have a number for one of the names.  Should look like 0=foo,1=bar");
        }
        int idx = Integer.valueOf(pieces[0]);
        if (idx >= nodePieces.size()) {
          throw new SsurgeonParseException("SplitWord got an index in -name which was larger than the largest possible split piece, " + idx + " (this is 0-indexed)");
        }
        this.nodeNames.put(idx, pieces[1]);
      }
    } else {
      this.nodeNames = Collections.emptyMap();
    }
  }

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

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