orm.go
func (idx *Index) Field(name string, options ...FieldOption) *Field {
	if field, ok := idx.fields[name]; ok {
		return field
	}
	fieldOptions := &FieldOptions{}
	fieldOptions = fieldOptions.withDefaults()
	fieldOptions.addOptions(options...)
	return idx.fieldWithOptions(name, fieldOptions)
}
func (idx *Index) Field(name string, options ...FieldOption) *Field {
	if field, ok := idx.fields[name]; ok {
		return field
	}
	fieldOptions := &FieldOptions{}
	fieldOptions = fieldOptions.withDefaults()
	fieldOptions.addOptions(options...)
	return idx.fieldWithOptions(name, fieldOptions)
}
// Field creates a Field struct with the specified name and defaults.