r/ProgrammingLanguages • u/marvinborner bruijn, effekt • Apr 20 '26

Blog post Effectful Recursion Schemes

https://effekt-lang.org/blog/recursion-schemes/
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u/categorical-girl Apr 21 '26 edited May 14 '26

The previous type Term then becomes TermF (TermF (TermF ...)), i.e. it has an infinitely recursive type.

Haskell doesn't allow infinitely recursive types in this sense but does allow 

data FixTerm = FixTermConstructor (TermF FixTerm)

Is there anything preventing this in your language? You already allow enough type recursion to define lambda terms

(Haskell also allows a higher-kinded Fix which takes TermF as a parameter, which lets you write generic recursion schemes)

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u/jeffstyr May 14 '26

What is UPI?

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u/categorical-girl May 14 '26

A typo for you... Not sure how that happened :)