Method flattenAndMergeMap

viper.go:1914–1943

flattenAndMergeMap recursively flattens the given map into a map[string]bool of key paths (used as a set, easier to manipulate than a []string): - each path is merged into a single key string, delimited with v.keyDelim - if a path is shadowed by an earlier value in the initial shadow map, it is skip

(shadow map[string]bool, m map[string]any, prefix string)

//
// The resulting set of paths is merged to the given shadow set at the same time.
func (v *Viper) flattenAndMergeMap(shadow map[string]bool, m map[string]any, prefix string) map[string]bool {
	if shadow != nil && prefix != "" && shadow[prefix] {
		// prefix is shadowed => nothing more to flatten
		return shadow
	}
	if shadow == nil {
		shadow = make(map[string]bool)
	}

	var m2 map[string]any
	if prefix != "" {
		prefix += v.keyDelim
	}
	for k, val := range m {
		fullKey := prefix + k
		switch val := val.(type) {
		case map[string]any:
			m2 = val
		case map[any]any:
			m2 = cast.ToStringMap(val)
		default:
			// immediate value
			shadow[strings.ToLower(fullKey)] = true
			continue
		}
		// recursively merge to shadow map
		shadow = v.flattenAndMergeMap(shadow, m2, fullKey)
	}
	return shadow
}

// mergeFlatMap merges the given maps, excluding values of the second map
// shadowed by values from the first map.