prestodb/presto · error · IllegalStateException

Unexpected numeric value in varchar enum signature

Error message

Unexpected numeric value in varchar enum signature

What it means

parseEnumMap rejects a digit or '-' in the value position when the enum is a varchar (non-bigint) enum. Numeric enum values are only legal when the signature declares a numeric base type; a bare number as a varchar enum's value is a parse error.

Source

Thrown at presto-common/src/main/java/com/facebook/presto/common/type/TypeSignature.java:477

                }
                else if (state == EnumMapParsingState.IN_STR_VALUE) {
                    state = EnumMapParsingState.EXPECT_COMMA_OR_CLOSING_BRACKET;
                }
                else {
                    throw new IllegalStateException("Cannot parse enum signature");
                }
            }
            else if (state == EnumMapParsingState.IN_KEY || state == EnumMapParsingState.IN_STR_VALUE) {
                keyOrValue.append(c);
            }
            else if (c == ':' && state == EnumMapParsingState.EXPECT_COLON) {
                key = keyOrValue.toString();
                keyOrValue = new StringBuilder();
                state = EnumMapParsingState.EXPECT_VALUE;
            }
            else if ((Character.isDigit(c) || c == '-') && state == EnumMapParsingState.EXPECT_VALUE) {
                if (!isBigintEnum) {
                    throw new IllegalStateException("Unexpected numeric value in varchar enum signature");
                }
                state = EnumMapParsingState.IN_NUM_VALUE;
                keyOrValue.append(c);
            }
            else if (Character.isDigit(c) && state == EnumMapParsingState.IN_NUM_VALUE) {
                keyOrValue.append(c);
            }
            else if ((c == ',' || c == '}') && (state == EnumMapParsingState.EXPECT_COMMA_OR_CLOSING_BRACKET || state == EnumMapParsingState.IN_NUM_VALUE)) {
                if (key == null) {
                    throw new IllegalStateException("Cannot parse enum signature");
                }
                map.put(key, keyOrValue.toString());
                if (c == '}') {
                    return new EnumMapParsingData(i, typeName, map, isBigintEnum);
                }
                key = null;
                keyOrValue = new StringBuilder();
                state = EnumMapParsingState.EXPECT_KEY;

View on GitHub (pinned to 55bb57d202)

Solutions

1. Quote the numeric value: 'ENUM<varchar>{a: "1"}'.
2. Or change the base type to a numeric one if values really are numbers: 'ENUM<bigint>{a: 1}'.
3. Regenerate the signature programmatically so value style always matches the base type.

Example fix

// before
"ENUM<varchar>{a: 1}"
// after
"ENUM<varchar>{a: \"1\"}"

// varchar enums must quote numeric-looking values
if (!signature.contains("ENUM<bigint>")) {
    // every ': ' value should start with '"' for varchar enums
    if (signature.matches(".*:\\s*[-0-9].*")) {
        throw new IllegalArgumentException("unquoted numeric value in varchar enum: " + signature);
    }
}

static boolean varcharEnumValuesQuoted(String sig) {
    if (sig == null || sig.contains("ENUM<bigint>")) return true;
    return !sig.matches(".*:\\s*[-0-9].*");
}

try {
    TypeSignature.parseTypeSignature(signature);
} catch (IllegalStateException e) {
    if (e.getMessage().contains("numeric value in varchar enum")) {
        // quote the values or switch base type to bigint
    } else throw e;
}

When it happens

Trigger: Parsing 'ENUM<varchar>{a: 1}' — a quoted-key enum whose value is an unquoted number — via TypeSignature.parseTypeSignature.

Common situations: Mixing enum styles when hand-writing signatures, code generators emitting numeric values without quoting them for varchar enums, copy/paste between bigint and varchar enum definitions.

Related errors

• Unexpected varchar value in numeric enum signature
• Cannot parse enum signature
• Bad type signature: '%s'
• Cannot parse distinct type definition(%s), expected '{' afte
• Cannot parse distinct type definition(%s), expected ',' afte

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/d8e7591561bec51d. Report an issue: GitHub.