A macro to replace the usual character entities (cf. SwiftUtilities) in the (XML notation) form &MY_CHARACTER_ENTITY;, returning the according text. (The ampersand can be escaped using a backslash, this escapement will be removed by ths macro.) You will get a compiler error if you have chosen a non-existing entity name.

Usage (note that the type annotation is not necessary):

let result: String = #ReplacingCharacterEntities("${auml}${alpha}")
print(result) // "äα"