stanfordnlp/CoreNLP · error · IllegalArgumentException

Not a valid quotes style:

Error message

Not a valid quotes style:

What it means

PTBLexer's options parser throws this IllegalArgumentException when the "quotes" option value cannot be converted to a LexerUtils.QuotesEnum constant via valueOf (after trimming and uppercasing). Only enum-constant names like unicode, ascii, original are accepted. This typically happens when configuring the PTBTokenizer through properties (e.g. tokenize.options or tokenizer options in CoreNLP).

Solutions

  1. Set quotes to one of the valid enum names: unicode, ascii, or original (case-insensitive).
  2. Check LexerUtils.QuotesEnum in your Stanford CoreNLP version for the exact accepted values (they changed across versions).
  3. Remove the quotes option entirely to use the default behavior if customization isn't needed.
  4. Wrap tokenizer construction in try-catch for IllegalArgumentException and log the accepted values.

Example fix

// before
Properties props = new Properties();
props.setProperty("tokenize.options", "quotes=curly,untokenizable=noneDelete"); // throws
// after
props.setProperty("tokenize.options", "quotes=unicode,untokenizable=noneDelete");
Defensive patterns

Strategy: validation

Validate before calling

// Pre-validate the quotes option against the enum
static void checkQuotesOption(String value) {
  try {
    edu.stanford.nlp.process.LexerUtils.QuotesEnum.valueOf(value.trim().toUpperCase(java.util.Locale.ROOT));
  } catch (IllegalArgumentException e) {
    throw new IllegalArgumentException("quotes must be one of " + java.util.Arrays.toString(edu.stanford.nlp.process.LexerUtils.QuotesEnum.values()) + ", got: " + value);
  }
}

Try / catch

try {
  PTBTokenizer<CoreLabel> tok = new PTBTokenizer<>(reader, options);
} catch (IllegalArgumentException e) {
  logger.error("Bad tokenizer option (allowed quotes values: unicode, ascii, original): {}", e.getMessage());
  throw e;
}

Prevention

When it happens

Trigger: Setting the tokenizer option quotes=<value> (via PTBTokenizer constructor options string, CoreNLP properties token.quote or tokenize options) with a value that is not a valid LexerUtils.QuotesEnum name, e.g. quotes=smart or quotes=curly.

Common situations: CoreNLP server/properties files using a quotes value copied from outdated documentation; typos like quote (singular) style names; passing human-friendly labels instead of the exact enum constants (UNICODE, ASCII, ORIGINAL).

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

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/7328398810d5867f. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/process/PTBLexer.flex:198

          } else if ("americanize".equals(key)) {
            americanize = val;
          } else if ("normalizeSpace".equals(key)) {
            normalizeSpace = val;
          } else if ("normalizeAmpersandEntity".equals(key)) {
            normalizeAmpersandEntity = val;
          } else if ("normalizeCurrency".equals(key)) {
            normalizeCurrency = val;
          } else if ("normalizeFractions".equals(key)) {
            normalizeFractions = val;
          } else if ("normalizeParentheses".equals(key)) {
            normalizeParentheses = val;
          } else if ("normalizeOtherBrackets".equals(key)) {
            normalizeOtherBrackets = val;
          } else if ("quotes".equals(key)) {
            try {
              quoteStyle = LexerUtils.QuotesEnum.valueOf(value.trim().toUpperCase(Locale.ROOT));
            } catch (IllegalArgumentException iae) {
              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);

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