you can imagine a version of Haskell that doesn’t have polymorphism or laziness, that only has unboxed integers, and as a result doesn’t need a GC. in such a la

you can imagine a version of Haskell that doesn’t have polymorphism or laziness, that only has unboxed integers, and as a result doesn’t need a GC. in such a language it’s still easy for the compiler to do stream fusion; whereas it’s still hard in C because the compiler needs to prove the loop doesn’t have side effects.