Benjamin Franksen writes:
Even in C++ using global variables is nowadays generally regarded as bad design, especially for libraries.
Well, to be fair one has to say that they are still quite popular although people call them "singletons" and other cute things these days. I distinctly remember reading hundreds and hundreds of articles which explained in great detail how to create and use them in slightly less than 200 lines of template meta-programming code without making the compiler explode and still getting the result you expected almost half of the time. Of course, if you used multi-threading it all exploded nonetheless then. So the discussion about global IO initializers in Haskell is slightly reminiscent of that for me. The argument in favor of global variables usually was that it was "more comfortable", which means that using them saved you a total of 20 seconds per-module because you had a parameter less to type every now and then, at the small cost of making your code almost unmaintainable in the long run. Frankly, the idea that anyone would want to jump through hoops to add them to a purely functional language sounds bizarre to me. But by all means, as long as the compiler extension is disabled per default I won't mind. :-) Peter