Questione giuridica chiave
Is the public-law appeal admissible against revocation of the residence permit and for a discretionary permit request?
Decisione estratta
The appeal was admissible only as to the revocation of the existing permit; it was inadmissible as to any discretionary request for a permit.
Motivazione estratta
A revoked permit that would otherwise continue to have effect can be challenged where federal or international law grants a derived right. No protected legal position existed for a discretionary permit under cantonal law.