> Lisp isn’t really a functional language — it’s a usual language that also has some functional ideas inside.
The idea that "functional language" means "purity" is something that was retconned onto functional programming in the 90s decades after Lisp had defined functional programming to mean programming in terms of expressions that produce values.
I like the ML/Miranda/Haskell lineage of languages a lot, but it really bugs me when people in that camp lay claim to some notion of being a "better" functional language than the older Lisp family. (Lispers, while smug about many other things, are generally less smug about how "pure" their languages' approach to functional programming is.)
This is like arguing that Lagavulin isn't "really" whiskey because real whiskeys are made in the US from corn mash.
Perl 5 has truthy values, and it came out a year (1994) before JS (1995). The idea probably appeared in Perl 1 (1987), and probably was borrowed from shell scripting, etc. It wouldn’t surprise me if “Truthy” predated unix.
The idea that "functional language" means "purity" is something that was retconned onto functional programming in the 90s decades after Lisp had defined functional programming to mean programming in terms of expressions that produce values.
I like the ML/Miranda/Haskell lineage of languages a lot, but it really bugs me when people in that camp lay claim to some notion of being a "better" functional language than the older Lisp family. (Lispers, while smug about many other things, are generally less smug about how "pure" their languages' approach to functional programming is.)
This is like arguing that Lagavulin isn't "really" whiskey because real whiskeys are made in the US from corn mash.