Humanizr/Humanizer · error · ArgumentException

Unrecognized number word: {unrecognizedWord}

Error message

Unrecognized number word: {unrecognizedWord}

What it means

This ArgumentException is thrown by InvertedTensWordsToNumberConverter.Convert when TryConvert fails. This converter handles locales whose compound tens place the unit before the tens token (e.g. Dutch-style 'eenentwintig' for 21). The error fires when the normalized phrase contains a token not in the locale's cardinal map, unit map, scale tokens, or ordinal map, and structural splitting (tens-linker decomposition, scale splitting, ordinal-suffix stripping) cannot resolve it.

Source

Thrown at src/Humanizer/Localisation/WordsToNumber/InvertedTensWordsToNumberConverter.cs:23

/// scales, ordinals, and optional ignored glue words in the same phrase.
/// </summary>
/// <remarks>
/// The parser normalizes the input first, removes one configured negative prefix, then resolves
/// either an exact ordinal token or a cardinal phrase composed from compact compounds and scale
/// words. The profile captures all locale-specific vocabulary so the algorithm can stay structural.
/// </remarks>
internal class InvertedTensWordsToNumberConverter(InvertedTensWordsToNumberProfile profile) : GenderlessWordsToNumberConverter
{
    const int MaximumParseDepth = 128;

    readonly InvertedTensWordsToNumberProfile profile = profile;

    /// <inheritdoc />
    public override long Convert(string words)
    {
        if (!TryConvert(words, out var parsedValue, out var unrecognizedWord))
        {
            throw new ArgumentException($"Unrecognized number word: {unrecognizedWord}");
        }

        return parsedValue;
    }

    /// <inheritdoc />
    public override bool TryConvert(string words, out long parsedValue) =>
        TryConvert(words, out parsedValue, out _);

    /// <inheritdoc />
    public override bool TryConvert(string words, out long parsedValue, out string? unrecognizedWord)
    {
        if (string.IsNullOrWhiteSpace(words))
        {
            throw new ArgumentException("Input words cannot be empty.");
        }

        var normalized = Normalize(words);

View on GitHub (pinned to ffc2b77c0f)

Solutions

1. Use TryToNumber(words, out value, culture, out unrecognizedWord) for any input that may contain errors.
2. Verify the locale's unit-part replacements and ordinal suffixes cover the input forms.
3. Check the unrecognizedWord output to locate the failing token and guide correction.
4. Ensure the culture matches the language of the words.

Example fix

// before
long value = text.ToNumber(new CultureInfo("nl"));

// after
if (!text.TryToNumber(out var value, new CultureInfo("nl"), out var bad))
    Console.WriteLine($"Unknown token: {bad}");

bool canParse = words.TryToNumber(out var value, culture, out var unrecognized);
if (!canParse)
    Console.WriteLine($"Unknown token: {unrecognized}");

static bool LooksLikeNumberWords(string words, CultureInfo culture) =>
    !string.IsNullOrWhiteSpace(words) && words.TryToNumber(out _, culture, out _);

try
{
    return words.ToNumber(new CultureInfo("nl"));
}
catch (ArgumentException ex) when (ex.Message.Contains("Unrecognized number word"))
{
    return 0;
}

When it happens

Trigger: Calling "words".ToNumber(culture) for an inverted-tens locale with a phrase containing a word not in the locale's vocabulary, a tens compound with an unknown linker, or a scale token the locale did not register.

Common situations: User-typed free-text input with misspellings or non-standard spellings; locale mismatch; compound words where the unit or tens fragment does not match after unit-part replacements; ordinal stems with suffixes not configured; Unicode or diacritic differences not handled by normalization.

Related errors

• Unrecognized number word: {unrecognizedWord}
• Unrecognized number word: {unrecognizedWord}
• Unrecognized number word: {unrecognizedWord}
• Unrecognized number word: {unrecognizedWord}
• Unrecognized number word: {unrecognizedWord}

AI-assisted analysis of Humanizr/Humanizer@ffc2b77c0f (2026-08-13). Data as JSON: /api/errors/a33a40e8291f03c2. Report an issue: GitHub.