nature

type Nature struct {
	Type            reflect.Type      // Type of the value. If nil, then value is unknown.
	Func            *builtin.Function // Used to pass function type from callee to CallNode.
	ArrayOf         *Nature           // Elem nature of array type (usually Type is []any, but ArrayOf can be any nature).
	PredicateOut    *Nature           // Out nature of predicate.
	Fields          map[string]Nature // Fields of map type.
	DefaultMapValue *Nature           // Default value of map type.
	Strict          bool              // If map is types.StrictMap.
	Nil             bool              // If value is nil.
	Method          bool              // If value retrieved from method. Usually used to determine amount of in arguments.
	MethodIndex     int               // Index of method in type.
	FieldIndex      []int             // Index of field in type.
}