stanfordnlp/CoreNLP · error · IllegalArgumentException

Not a valid dashes style

Error message

Not a valid dashes style: ${value}

What it means

IllegalArgumentException from PTBLexer option parsing when the value given for the 'ellipses' option (or dashes style option) cannot be parsed into the corresponding LexerUtils enum; the options string passed to the tokenizer is invalid.

Solutions

1. Use an exact LexerUtils.DashesEnum constant name (case-insensitive), e.g. dashes=unicode.
2. Correct typos and remove decorators like '-dash' from the value.
3. Align quotes/ellipses/dashes values to the same enum family supported by your CoreNLP version.

Example fix

// before
props.setProperty("tokenize.options", "dashes=em-dash");
// after
props.setProperty("tokenize.options", "dashes=unicode");

boolean ok = Arrays.stream(LexerUtils.DashesEnum.values()).anyMatch(e -> e.name().equalsIgnoreCase(value.trim()));
if (!ok) throw new IllegalArgumentException("dashes must be a LexerUtils.DashesEnum name");

try { new PTBTokenizer<>(reader, factory, "dashes=" + style); } catch (IllegalArgumentException e) { if (e.getMessage().contains("dashes style")) { /* use default */ } else throw e; }

When it happens

Trigger: Option map entry key="dashes" with a value outside DashesEnum, e.g. dashes=em-dash, dashes=hyphen, or dashes=unicode; (note the message text; the option here is dashes).

Common situations: Configuring normalization of dashes/quotes/ellipses together and using one consistent-but-wrong style name for all three; older ASCII-only expectations ported to newer CoreNLP where enum names differ.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• Not a valid ellipses style:
• Not a valid ellipses style:
• Not a valid ellipses style
• Not a valid quotes style:
• Not a valid quotes style

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/32ad1be359b57241. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/process/PTBLexer.java:61141

              throw new IllegalArgumentException ("Not a valid quotes style: " + value);
            }
          } else if ("splitAssimilations".equals(key)) {
            splitAssimilations = val;
          } else if ("splitHyphenated".equals(key)) {
            splitHyphenated = val;
          } else if ("splitForwardSlash".equals(key)) {
            splitForwardSlash = val;
          } else if ("ellipses".equals(key)) {
            try {
              ellipsisStyle = LexerUtils.EllipsesEnum.valueOf(value.trim().toUpperCase(Locale.ROOT));
            } catch (IllegalArgumentException iae) {
              throw new IllegalArgumentException ("Not a valid ellipses style: " + value);
            }
          } else if ("dashes".equals(key)) {
            try {
              dashesStyle = LexerUtils.DashesEnum.valueOf(value.trim().toUpperCase(Locale.ROOT));
            } catch (IllegalArgumentException iae) {
              throw new IllegalArgumentException ("Not a valid dashes style: " + value);
            }
          } else if ("escapeForwardSlashAsterisk".equals(key)) {
            escapeForwardSlashAsterisk = val;
          } else if ("untokenizable".equals(key)) {
            switch (value) {
              case "noneDelete":
                untokenizable = UntokenizableOptions.NONE_DELETE;
                break;
              case "firstDelete":
                untokenizable = UntokenizableOptions.FIRST_DELETE;
                break;
              case "allDelete":
                untokenizable = UntokenizableOptions.ALL_DELETE;
                break;
              case "noneKeep":
                untokenizable = UntokenizableOptions.NONE_KEEP;
                break;
              case "firstKeep":

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