Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder2.enfer-du-nord.net!feeder.news-service.com!news2.euro.net!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.000 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'python,': 0.01; 'function,': 0.07; 'received:verizon.net': 0.07; 'semantic': 0.07; 'terry': 0.07; 'python': 0.08; '(also': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:80.91.229.12': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'received:lo.gmane.org': 0.09; 'am,': 0.12; 'library': 0.15; '9:13': 0.16; '9:15': 0.16; 'default).': 0.16; 'fp:': 0.16; 'reedy': 0.16; 'semantically': 0.16; 'side-effects': 0.16; 'subject:OOP': 0.16; 'syntactic': 0.16; 'syntactical': 0.16; 'wrote:': 0.16; '>>>': 0.18; 'functions,': 0.18; 'jan': 0.19; 'programming': 0.20; 'math': 0.21; 'header:In-Reply-To:1': 0.22; '(or': 0.23; 'sep': 0.23; 'somehow': 0.23; 'suggests': 0.23; 'pm,': 0.24; 'suggestion': 0.26; '(in': 0.26; 'function': 0.27; 'separate': 0.28; 'depends': 0.28; 'problem': 0.28; 'not.': 0.30; 'functional': 0.31; 'objects': 0.32; 'does': 0.32; 'usually': 0.32; 'source': 0.33; 'sort': 0.33; 'to:addr:python-list': 0.33; 'header:User-Agent:1': 0.34; 'requirements': 0.34; 'staying': 0.34; 'header:X-Complaints-To:1': 0.35; 'uses': 0.35; '(for': 0.35; 'object': 0.35; 'problems': 0.36; 'skip:" 10': 0.36; 'none': 0.37; 'depend': 0.37; 'languages': 0.37; 'using': 0.37; 'but': 0.37; 'could': 0.38; 'received:org': 0.38; 'returning': 0.38; 'somewhat': 0.38; 'some': 0.38; 'subject:: ': 0.39; 'header:Mime- Version:1': 0.39; 'to:addr:python.org': 0.39; 'called': 0.40; 'procedures': 0.64; 'believe': 0.65; 'procedure.': 0.67; 'william': 0.68; 'wish': 0.69; 'research,': 0.82; 'distinguish': 0.84; 'moment)': 0.84; 'rusi': 0.84 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Terry Reedy Subject: Re: Functions vs OOP Date: Mon, 05 Sep 2011 18:55:36 -0400 References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: pool-74-109-121-73.phlapa.fios.verizon.net User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0) Gecko/20110812 Thunderbird/6.0 In-Reply-To: X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 46 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1315263399 news.xs4all.nl 2529 [2001:888:2000:d::a6]:57209 X-Complaints-To: abuse@xs4all.nl Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:12795 On 9/5/2011 1:45 PM, William Gill wrote: > On 9/4/2011 9:13 AM, rusi wrote: >> On Sep 3, 9:15 pm, William Gill wrote: >>> During some recent research, and re-familiarization with Python, I came >>> across documentation that suggests that programming using functions, and >>> programming using objects were somehow opposing techniques. >> >> Staying with (for the moment) the suggestion that OO-P and F-P are >> complementary, I believe it is worthwhile to distinguish syntactic OO- >> P vs F-P from semantic OO-P vs F-P. >> >> Syntactically: f(x) is functional x.f() is object oriented. >> Semantically if f's return value depends only on x ie does not depend >> on state it is functional (in the math sense) -- the jargon is that f >> is referentially transparent. > > Not to split hairs, but syntactically f(x) is a function in many > programming paradigms. > > As I understand it functional programming places specific requirements > on functions, i.e.referential transparency. So f(x) may or may not be > "functional". In Python, it may be a parameterized procedure. Some languages separate functions and procedures (also called subroutines). Python does not. (Or you could say that it makes procedures into functions with side-effects by returning None by default). > x.f() is also a function, but it is a member of the object x, is > referred to as a 'method' of x, and uses the syntactical "dot" notation > object"dot"function for identification. > >> Referential opaqueness is usually such a source of problems that it >> turns out good to contain the problem somewhat -- hence the wish for >> encapsulation. >> >> One can find in the python library itself all 4 combinations: >> syntactically and semantically OO : sort >> syntactically and semantically FP: sorted >> syntactically OO semantically FP: join > -- Terry Jan Reedy