In Haskell you can easily fake an environment with a bunch of mutable global variables avaliable throughout the program, although this is frowned upon. Since gl

In Haskell you can easily fake an environment with a bunch of mutable global variables avaliable throughout the program, although this is frowned upon. Since global mutable variables are discouraged even in imperative languages, I agree that the argument is a strawman. There is however a nice property that Haskell makes it explicit in the type signature if global mutable state is available to the function. This makes it a lot easier to guarantee that large parts of a program is indeed side-effect free.