Signatures use named types

A function, action or query can't take or return a built-in representation type directly. Text, Int, Bool, Uuid, the time types, and the forms of them that may be none, are each wrapped in a named type that says what the value means.

type CustomerNote = Text {    max_length: 500}type NoteWasEdited = Bool {}function edited(before: CustomerNote, after: CustomerNote) -> NoteWasEdited {    return NoteWasEdited(before != after)}

Email, Url, IpAddress, objects, enums, field types and Unit are allowed. Inside a body, local variables can still hold built-in types.