Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder1.news.weretis.net!feeder.erje.net!eu.feeder.erje.net!xlned.com!feeder1.xlned.com!newsfeed.xs4all.nl!newsfeed3.news.xs4all.nl!xs4all!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; 'languages,': 0.04; 'subject:Python': 0.05; 'bash': 0.07; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'scripting': 0.09; 'subject:language': 0.09; 'subset': 0.09; 'terry': 0.09; 'language': 0.14; 'arrays,': 0.16; 'awk': 0.16; 'conditional': 0.16; 'expressions.': 0.16; 'looping': 0.16; 'loops': 0.16; 'non-trivial': 0.16; 'operation,': 0.16; 'presume': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'reedy': 0.16; 'sed': 0.16; 'subject:programming': 0.16; 'syntax,': 0.16; 'wrote:': 0.17; 'variables': 0.17; 'jan': 0.18; 'tim': 0.18; 'explicit': 0.22; 'implicit': 0.22; 'programming': 0.23; "haven't": 0.23; 'machine': 0.24; 'header:In-Reply-To:1': 0.25; 'header:User-Agent:1': 0.26; 'language.': 0.27; 'separate': 0.27; 'header:X-Complaints-To:1': 0.28; 'assert': 0.29; 'complete,': 0.29; 'probably': 0.29; "i'm": 0.29; 'that.': 0.30; 'implement': 0.32; 'to:addr:python-list': 0.33; 'languages': 0.33; 'pm,': 0.35; 'subject:?': 0.35; 'something': 0.35; 'received:org': 0.36; 'michael': 0.36; 'but': 0.36; 'subject:: ': 0.38; 'sure': 0.38; 'to:addr:python.org': 0.39; 'where': 0.40; 'header:Received:5': 0.40; 'most': 0.61; 'life,': 0.62; 'show': 0.63; 'covers': 0.65; 'harder': 0.65; 'category.': 0.84; 'received:fios.verizon.net': 0.84; 'recursion,': 0.84; 'execution,': 0.91 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Terry Reedy Subject: Re: Is Python programming language? Date: Sat, 09 Feb 2013 21:40:11 -0500 References: <1360328631.24677.YahooMailClassic@web125203.mail.ne1.yahoo.com> <6lmdh8t7osnvjj5v5vnrav8q5anum6ln3q@4ax.com> <5116E168.6030707@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: pool-173-75-251-66.phlapa.fios.verizon.net User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130107 Thunderbird/17.0.2 In-Reply-To: <5116E168.6030707@gmail.com> X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 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: 22 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1360464050 news.xs4all.nl 6840 [2001:888:2000:d::a6]:52333 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:38544 On 2/9/2013 6:53 PM, Michael Torrie wrote: > On 02/09/2013 04:26 PM, Tim Roberts wrote: >> Most people would call bash a "scripting language", but it is also clearly >> a programming language. It has syntax, variables and expressions. I >> suspect it is Turing-complete, although I haven't seen a proof of that. >> >> I would assert that scripting languages are a proper subset of programming >> languages, not a separate category. > > I'm pretty sure Bash is turing complete. I know it's been shown that > sed is turing complete, and awk probably is too! If I recall, the way > to show a language is turing complete is to implement a turing machine If the language has arrays, conditional execution, and explicit (while) loops or recursion, you can be pretty sure it is Turing complete. I presume this covers awk and bash. Something like the game of Life, where the looping in implicit in the operation, is much harder to show Turing complete. I suspect sed is non-trivial also. -- Terry Jan Reedy