On Wed, Oct 4, 2017 at 5:07 AM, bartc <b...@freeuk.com> wrote: > It is just being elitist. I have a preference for keeping things simple and > avoiding unnecessary complexity. But with programming languages many do have > a penchant for the latter. > > As an example, a recent discussion on comp.lang.c was about implementing > named constants. I proposed one very simple way of doing it, other people > were talking about using #define, enum, const, static const, or importing > constexpr and special rules for 'const' from C++. All unsatisfactory and > each having their own problems. > > For that matter, I don't think Python has such a feature either. So that you > write for example: > > const C = 123345 > > and then whenever C appears within the code, it's implemented as: > > LOAD_CONST (123345) > > I'm pretty sure that there are very complicated ways of achieving something > similar, maybe with all your decorators, or using PyMacro or whatever. But > not doing it straightforwardly. [Python's design makes a simple > implementation harder.]
Python has the simplest named constants of all: C = 12345 As long as you don't subsequently change it, it's a constant. And it's very simple because it works just like any other variable. Python also has a particularly flexible Enum implementation, but if you don't want it then don't use it. >> You don't think that adding a cache for an expensive function is >> programming? >> >> If you had ten expensive functions, and you wanted to add a cache to each >> of >> them, would you write out ten separate caches (probably copying and >> pasting >> the code each time)? >> >> Or would you write a function that builds a cache and adds it to the >> expensive >> function *once*, then call it ten times, once for each function being >> wrapped? > > > I'm trying to think of a real example where I've had to add a cache to to a > function, whatever that even means (memoisation?). You've never used a dynamic programming algorithm? >> That you think that this is not programming is an indictment off your >> programming skills. These sorts of functional programming techniques go >> back >> to the 1950s, Lisp is literally the second oldest high-level language ever >> (only Fortran is older). You may or may not have been a hotshot in your >> little corner of the programming world, but there's an entire world out >> there. > > > What other languages apart from Python have equivalent features to > decorators and, what's the other one, descriptors? Apart from Lisp. Literally any language with first-class function types, whether they have the @decorator-style syntactic sugar for it or not. Descriptors are a bit unique to Python, I'll grant, but mostly they're just used in the form of properties. Here's a list of languages that support properties: https://en.wikipedia.org/wiki/Property_(programming)#Example_syntax -- https://mail.python.org/mailman/listinfo/python-list
