What causes "GetFloatFromMap: key [%s] not found" in zincsearch/zincsearch?

Add the missing numeric key (named in the error) to the filter's settings map.

GetFloatFromMap: key [%s] not found

Error message

GetFloatFromMap: key [%s] not found

What it means

GetFloatFromMap reads a numeric option from a filter settings map (used by dict, edge_ngram, length, ngram, shingle, truncate filters). This error means the required key is not present at all. It is a missing-required-option error surfaced while constructing a token filter.

Source

Thrown at pkg/zutils/map.go:49

}

func GetBoolFromMap(m interface{}, key string) (bool, error) {
	v, err := GetAnyFromMap(m, key)
	if err != nil {
		return false, fmt.Errorf("GetBoolFromMap: key [%s] not found", key)
	}
	vs, ok := v.(bool)
	if !ok {
		return false, fmt.Errorf("GetBoolFromMap: value [%s] shuld be a bool", key)
	}

	return vs, nil
}

func GetFloatFromMap(m interface{}, key string) (float64, error) {
	v, err := GetAnyFromMap(m, key)
	if err != nil {
		return 0, fmt.Errorf("GetFloatFromMap: key [%s] not found", key)
	}
	vs, ok := v.(float64)
	if !ok {
		return 0, fmt.Errorf("GetFloatFromMap: value [%s] should be a float64", key)
	}

	return vs, nil
}

func GetStringSliceFromMap(m interface{}, key string) ([]string, error) {
	v, err := GetAnyFromMap(m, key)
	if err != nil {
		return nil, fmt.Errorf("GetStringSliceFromMap: key [%s] not found", key)
	}
	var vs []interface{}
	switch v := v.(type) {
	case []string:
		return v, nil

View on GitHub (pinned to dd2f8afd65)

Solutions

Add the missing numeric key (named in the error) to the filter's settings map.
Check the option name spelling against the filter's documentation.
Provide defaults for optional numeric params in a wrapper before calling the constructor.
Validate the filter definition against an expected-option schema before construction.

Example fix

// before
{"type": "ngram"}

// after
{"type": "ngram", "min_gram": 2, "max_gram": 3}

Defensive patterns

Strategy: validation

Validate before calling

func requireNumeric(m map[string]interface{}, key string) error {
    v, ok := m[key]
    if !ok {
        return fmt.Errorf("required numeric option %q missing", key)
    }
    if _, ok := v.(float64); !ok {
        return fmt.Errorf("option %q must be a number, got %T", key, v)
    }
    return nil
}
// requireNumeric(settings, "min_gram")

Try / catch

min, err := zutils.GetFloatFromMap(settings, "min_gram")
if err != nil {
    if strings.Contains(err.Error(), "not found") {
        return fmt.Errorf("ngram filter requires min_gram/max_gram: %w", err)
    }
    return err
}

Prevention

Keep a per-filter-type required-option checklist (e.g. ngram needs min_gram and max_gram).
Validate filter definitions against a schema before calling constructors.
Test each filter definition with a constructor call in unit tests using fixture configs.
When changing filter types, update the whole option set, not just the type field.

When it happens

Trigger: Calling GetFloatFromMap via NewDictTokenFilter, NewEdgeNgramTokenFilter, NewLengthTokenFilter, NewNgramTokenFilter, NewShingleTokenFilter, or NewTruncateTokenFilter when the settings map lacks the numeric option (e.g. "min_gram", "max_gram", "preserve_original").

Common situations: Writing a token filter definition that omits a required numeric parameter (e.g. an ngram filter with no min_gram); typos in the option name; switching filter types without updating the option set.

Related errors

AI-assisted analysis of zincsearch/zincsearch@dd2f8afd65 (2026-09-03). Data as JSON: /api/errors/8b35197bb5889610. Report an issue: GitHub.