On Tuesday, March 29, 2016 at 12:18:38 AM UTC+5:30, Paul Rubin wrote: > BartC writes: > > With more recent ones I've dropped that model, so that statements and > > expressions are different, and that is strictly enforced. This makes > > implementation simpler, and detects lots more errors. > > You should try Haskell, where there are only expressions, but the ones > that perform actions can be separated from the other ones through the > type system, so using one in the wrong place raises a compile time type > error.
When I studied Pascal was mainstream and Lisp (and to smaller extent Prolog, APL) were hi-faluting. In retrospect, Pascal got something right that most everyone, both before and after got wrong, viz that we need values AND effects. Philosophically: Is programming about knowing or doing? Clearly any onesided answer is wrong. Both columns in the table here need equal weightage http://blog.languager.org/2016/01/primacy.html#expstat Pascal → C → Python is a slide down because Pascal had the clear distinction of procedure and function C conflated procedure into function with its 'void function' [Actually the first C had no void] Python only has None-return But a None returned to signify a real semantics eg dict.get not finding key And a None returned because asking for something is meaningless eg print in python3 are unfortunately undistinguishable although conceptually totally different Yeah Haskell's type system carries Pascal's procedure←→function distinction in great and excruciating detail -- pure and monadic types. But IMHO monads for distinguishing values and effects is sledgehammer-for-cracking-an-egg -- https://mail.python.org/mailman/listinfo/python-list
