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One of my favorite features of Haskell is that I can use where to write the auxiliary function definitions after the code that use them, but keep them scoped in
by mrgriffin 8y ago
One of my favorite features of Haskell is that I can use where to write the auxiliary function definitions after the code that use them, but keep them scoped inside of a single function.
A relatively bad example here: https://wiki.haskell.org/Worker_wrapper#Hiding_the_worker https://wiki.haskell.org/Worker_wrapper#Hiding_the_worker
- yawaramin 8y agoBindings in the `where` clause can still access names in the main binding: https://wiki.haskell.org/Let_vs._Where#Advantages_of_where https://wiki.haskell.org/Let_vs._Where#Advantages_of_where This runs the risk of strongly coupling them to the main binding and making them less reusable. IMHO strong coupling where two bindings are aware of each others' internals should be avoided.
- cannabis_sam 8y agoLike your link says: doesn’t lambda lifting solve that problem? That’s what I always do if I want to move an auxillary function to the top-level for reusing elsewhere.
- yawaramin 8y agoIndeed, I also prefer lifting, especially internally inside a module. It jives with the idea of loose coupling, strong cohesion.