Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.mixmin.net!newsfeed.fsmpi.rwth-aachen.de!newsfeed.kamp.net!newsfeed.kamp.net!feeder1.cambriumusenet.nl!feed.tweaknews.nl!194.109.133.83.MISMATCH!newsfeed.xs4all.nl!newsfeed4a.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 0.001 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'anyway.': 0.05; 'subject:Python': 0.06; 'indexing': 0.07; 'subject: -- ': 0.07; 'utf-8': 0.07; 'string': 0.09; 'cc:addr:python-list': 0.11; 'thread': 0.14; "wouldn't": 0.14; '-tkc': 0.16; 'cached': 0.16; 'caching': 0.16; 'elsewhere,': 0.16; 'expects': 0.16; 'from:addr:python.list': 0.16; 'from:addr:tim.thechases.com': 0.16; 'from:name:tim chase': 0.16; 'internally': 0.16; 'loops': 0.16; 'operation,': 0.16; 'operation.': 0.16; 'rarely': 0.16; 'index': 0.16; 'wrote:': 0.18; 'touch.': 0.19; 'cc:addr:python.org': 0.22; 'non': 0.24; 'cc:2**0': 0.24; 'cc:no real name:2**0': 0.24; "i've": 0.25; '(see': 0.26; 'header:In- Reply-To:1': 0.27; 'idea': 0.28; 'streaming': 0.30; 'waste': 0.30; "i'm": 0.30; 'code': 0.31; 'bad.': 0.31; 'subject:skip:i 10': 0.31; "i'd": 0.34; 'could': 0.34; 'operations': 0.35; 'but': 0.35; 'charset:us-ascii': 0.36; 'recent': 0.39; 'space': 0.40; 'algorithms': 0.60; 'most': 0.60; 'mentioned': 0.61; 'simple': 0.61; 'world': 0.66; 'side': 0.67; 'everything,': 0.84; 'received:50.22': 0.84; 'besides,': 0.93 Date: Wed, 4 Jun 2014 07:25:36 -0500 From: Tim Chase To: Marko Rauhamaa Subject: Re: Micro Python -- a lean and efficient implementation of Python 3 In-Reply-To: <8761kgvqdr.fsf@elektro.pacujo.net> References: <20140603194949.3147497d@x34f> <44acd692-5dcd-4e5f-8238-7fbe0de4db2a@googlegroups.com> <538ecdef$0$11109$c3e8da3@news.astraweb.com> <7xoay9w1h0.fsf@ruckus.brouhaha.com> <8761kgvqdr.fsf@elektro.pacujo.net> X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - boston.accountservergroup.com X-AntiAbuse: Original Domain - python.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tim.thechases.com X-Get-Message-Sender-Via: boston.accountservergroup.com: authenticated_id: tim@thechases.com Cc: python-list@python.org 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: 24 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1401884774 news.xs4all.nl 2833 [2001:888:2000:d::a6]:39374 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:72632 On 2014-06-04 14:57, Marko Rauhamaa wrote: > > If you use UTF-8 for everything, then you end up in a world where > > string-indexing (see ChrisA's other side thread on this topic) is > > no longer an O(1) operation, but an O(N) operation. > > Most string operations are O(N) anyway. Besides, you could try and > be smart and keep a recent index cached so simple for loops would > be O(N) instead of O(N**2). So the idea of keeping strings > internally in UTF-8 might not be all that bad. As mentioned elsewhere, I've got a LOT of code that expects that string indexing is O(1) and rarely are those strings/offsets reused I'm streaming through customer/provider data files, so caching wouldn't do much good other than waste space and the time to maintain them. If I knew that string indexing was O(something non constant), I'd have retooled my algorithms to take that into consider, but that would be a lot of code I'd need to touch. -tkc