Dr. Ralf Laemmel Advanced FP - The Expression Problem

original source: channel9.msdn.....
"The Expression Problem is a new name for an old problem. The goal is to define a datatype by cases, where one can add new cases to the datatype and new functions over the datatype, without recompiling existing code, and while retaining static type safety (e.g., no casts)." - Philip Wadler
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[@a0um]

This talk confirms to me that the “expression problem” should have been called “extensibility problem”.
I suspect this is a case where the excitement of coming up with a world play won over the goal of correctly expressing the essence of the problem. “Expression” problem refers to the context in which it was first formalized (implementing programming language interpreters).

[@a0um]

I can’t find the continuation of this video where it actually shows the Haskell solution to the expression problem. 🙁

[@grantsmith3653]

I was wondering the same thing. I can't find it either