Is there a reason (performance, memory, typesystem) why a Tuple is not a HList and Function is not a mapping form a HList to some value?
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Is there a reason (performance, memory, typesystem) why a Tuple is not a HList and Function is not a mapping form a HList to some value?
Performance and memory both. Tuples have
O(1)access for their elements; as typically constructed,HListis a list, and thus hasO(n). Also, tuples require memory for one extra object withnreferences to other objects, whileHList(as a list) requires one object each (plus anextpointer). Since the overhead of an object is about two references, this turnsn+2memory usage into4n+2. Not so awesome for a core language construct.