Patent claims define the legal scope: if "using Swift" isn't in the claims then using another language, provided it fits the language of the claims, is also covered by the patent.
Also, "using Swift" isn't in the claims ¯\_(ツ)_/¯
When drafting the claims writer (patent attorney or agent usually) will add clauses to work around prior art. You can't just add unrelated features though, the features need to have synergy to represent a single invention.
[I've read a lot on USA patents but only worked directly with UK and EU patents.
This is not legal advice.]