I read the linked article, and found it rather confusing. For example, what does "In order to write a lot of small definitions you have to have a stack" mean? e

I read the linked article, and found it rather confusing. For example, what does "In order to write a lot of small definitions you have to have a stack" mean? e.g. in Haskell lots of functions are very small compositions of existing functions, like "foo = filter bar . map baz". But it's definitely not stack based! I'm also confused about the "local variables are harmful" mentality. Why? They may not suit concatenative languages, but I find naming things serves as effective 'documentation'. Or is the point that these should be put in separate functions? But that also sounds wrong, because then you greatly complicate the control flow and spread everything to many places. Furthermore, isn't something like that A register 'just' a local variable (or worse: a mutable global variable)? I find the dismissal of things like files and encryption disturbing. Many programs need some form of persistence. How is that useless? Why does 'needed data' not need to be encrypted?!?