Re:Why Reliability Demands Functional Programming
by jesse__ on Sunday December 28, 2025 @03:36PM
(#46414244)
Okay .. so, riddle me this Batman.
If I have an untagged union in <language_of_your_choice>, and I'm iterating over an array of elements of type `Foo|Bar|Baz`, and I have to do a dynamic cast before accessing the element (runtime typecheck) .. I believe that must actually be a tagged union under the hood, whether or not you call it a tagged union or not... right? ie. How would the program possibly know at runtime what the type of a heterogeneous set of elements is without a tag value to tell it?
If I have an untagged union in <language_of_your_choice>, and I'm iterating over an array of elements of type `Foo|Bar|Baz`, and I have to do a dynamic cast before accessing the element (runtime typecheck) .. I believe that must actually be a tagged union under the hood, whether or not you call it a tagged union or not... right? ie. How would the program possibly know at runtime what the type of a heterogeneous set of elements is without a tag value to tell it?