'utilities.ts' is an API surface hazard

utilities.ts consists of 4 different namespaces:

• one which seems to be entirely internal
• one which is entirely exposed
• one which is entirely exposed and is entirely type predicate functions
• one which is a random assortment of internal and exposed functions that have no consistent usage

Just from my intuition and experience, I don't think this is a good idea. It's just too easy to put a new helper in some random section of the file and forget whether or not it's being exposed.

As a naive first approximation, here's what I think would be more appropriate for each respective namespace:

• utilities.ts
• publicUtilities.ts
• publicPredicates.ts
• I don't know, TBD.

Inizia leggendo utilities.ts e cataloga i quattro namespace, annotando quali funzioni sono interne, esposte o predicati di tipo. Definisci una destinazione coerente per ogni gruppo, incluso il namespace misto attualmente irrisolto. Il lavoro è completato quando l'organizzazione delle utility e i confini di esposizione sono chiari e applicati in modo coerente.