Hi everybody! To understand monads (of which ordinary lists are a good example), I do think you need to understand the spirit in which category theory conduct mathematical investigations. A very good/easy essay to read, which I highly recommend is http://www.math.harvard.edu/~mazur/preprints/when_is_one.pdf .
best wishes Mikael Hall 2010/1/21 Dan Bron <[email protected]> > > Passing a file name as an argument but working on the file itself looks > a > > lot like using a global variable - which would violate the strict > functional > > paradigm. > > Right, and functional programmers dislike IO for the same kinds of reason > they dislike global variables. But not for exactly the > same reason (one big difference is that a program can control its own > variables [and hence can abstract them away], but won't > control "the state of the world"). > > > I notice the article you cited talks about updating a database by > > passing the database as an argument - not just a reference to the > database. > > Exactly! > > -Dan > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- "No, no, you're not thinking; you're just being logical." — Niels Bohr "There are two kinds of people, those who finish what they start and so on." — Robert Byrne ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
