Comment by ptx

This thread appears to be conflating two different things: whether a language is a "purely functional language" and whether the language's functions are "pure functions".

Presumably a purely functional language would, it seems to me, be exclusively (i.e. purely) functional, i.e. the functions in the language would always be pure. A language that has pure functions and impure functions, on the other hand, would not be "purely functional" as it contains impure parts, but it could still contain pure parts as well.

The issue with V seems to be that, although everyone agrees that it contains impure parts and thus is not a "purely functional language", the supposedly "pure functions" are also not actually pure, according to some reasonable definitions of purity.