Humanizr/Humanizer · error · InvalidOperationException

Inflection rule '{id}' scope must target standalone nouns.

Error message

Inflection rule '{id}' scope must target standalone nouns.

What it means

A rule's 'scope' must have 'pos: noun' and 'token: standalone'. The engine only applies productive rules to standalone noun tokens. ParseRules throws when either field differs.

Source

Thrown at src/Humanizer.SourceGenerators/Generators/ProfileCatalogs/InflectionCatalogParsing.cs:453

                }

                ValidateSources(rule, sourceIds, $"Inflection rule '{id}'");
                var direction = GetRequiredScalar(rule, "direction", $"Inflection rule '{id}' must define direction");
                if (direction is not ("forward" or "reverse"))
                {
                    throw new InvalidOperationException($"Inflection rule '{id}' has unsupported direction '{direction}'.");
                }

                var priority = GetRequiredInt(rule, "priority", $"Inflection rule '{id}' must define priority");
                var scope = GetRequiredMapping(rule, "scope", $"Inflection rule '{id}' must define scope");
                ValidateProperties(
                    scope,
                    $"Inflection rule '{id}' scope",
                    "pos", "countability", "token", "scripts");
                if (GetRequiredScalar(scope, "pos", $"Inflection rule '{id}' scope must define pos") != "noun" ||
                    GetRequiredScalar(scope, "token", $"Inflection rule '{id}' scope must define token") != "standalone")
                {
                    throw new InvalidOperationException(
                        $"Inflection rule '{id}' scope must target standalone nouns.");
                }

                var countabilities = GetRequiredStrings(
                    scope,
                    "countability",
                    $"Inflection rule '{id}' scope must define countability");
                foreach (var countability in countabilities)
                {
                    if (!Countabilities.Contains(countability))
                    {
                        throw new InvalidOperationException(
                            $"Inflection rule '{id}' scope countability '{countability}' is unsupported.");
                    }
                }
                var ruleScripts = GetRequiredStrings(
                    scope,
                    "scripts",

View on GitHub (pinned to ffc2b77c0f)

Solutions

1. Set 'scope.pos: 'noun'' and 'scope.token: 'standalone''

Example fix

# before
        scope:
          pos: 'noun'
          token: 'phrase'
# after
        scope:
          pos: 'noun'
          token: 'standalone'

foreach (var rule in rules)
    if (rule.Scope.Pos != "noun" || rule.Scope.Token != "standalone")
        Report($"{locale}: rule '{rule.Id}' scope must target standalone nouns.");

static bool ScopeIsStandaloneNoun(Scope sc) =>
    sc.Pos == "noun" && sc.Token == "standalone";

When it happens

Trigger: scope has 'pos:' other than 'noun', or 'token:' other than 'standalone' (e.g. 'token: phrase').

Common situations: Copying a fixture and changing token to 'phrase'; modeling a non-noun rule before the engine supports it.

Related errors

• Inflection defines unsupported quantity selector; expected '
• Inflection quantitySelector 'exact-numeric-singleton' requir
• Inflection quantitySelector 'exact-numeric-singleton' cannot
• Inflection display category 'one' is unreachable without qua
• Active inflection bundle must define lexemes.

AI-assisted analysis of Humanizr/Humanizer@ffc2b77c0f (2026-08-13). Data as JSON: /api/errors/f9ffd5b262cce4fc. Report an issue: GitHub.