[ionfish]

Not to nitpick overmuch, but if functional, object-oriented and logic are the other styles of programming language, then surely the correct adjective to describe Fortran is procedural? Object-oriented languages are also generally imperative—the contrasting term is declarative, which purely functional and logic programming languages are (to some extent).

Interestingly, given the conclusions reached in the article, both Sterling and Shapiro's The Art of Prolog and Lloyd's Foundations of Logic Programming mention the Japanese fifth generation project as an example of Prolog's impending breakthrough into the mainstream.

[DannoHung]

There is no real restriction that an object oriented language be imperative and, rule of Demeter aside, I think it's been sort of agreed that always returning a value as a result of any given method invocation makes OO languages much nicer (even if side-effects take place as well). However, procedural implies imperative, I believe.

In any case, I always thought language classifications could get a little fuzzy.

[davidmathers]

surely the correct adjective to describe Fortran is procedural

No, the original FORTRAN that the author is referring to wasn't procedural. FORTRAN II, a few years later, added subroutines to the language.