Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!xlned.com!feeder5.xlned.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 0.093 X-Spam-Evidence: '*H*': 0.82; '*S*': 0.00; '(at': 0.04; 'python)': 0.05; 'indexing': 0.07; 'subject:PEP': 0.07; 'welcome.': 0.07; 'check,': 0.09; 'python': 0.11; "'break'": 0.16; "'for',": 0.16; '(note:': 0.16; 'true:': 0.16; 'thanks.': 0.20; 'portion': 0.22; 'effort.': 0.24; "shouldn't": 0.24; 'least': 0.26; 'to:2**1': 0.27; 'to:no real name:2**1': 0.29; "doesn't": 0.30; "i'm": 0.30; 'code': 0.31; 'comments': 0.31; 'argue': 0.31; 'motivation': 0.31; 'themselves': 0.32; 'run': 0.32; 'sense': 0.34; 'could': 0.34; 'convert': 0.35; 'etc.)': 0.35; 'but': 0.35; 'much.': 0.36; 'charset:us-ascii': 0.36; 'possible': 0.36; 'too': 0.37; 'being': 0.38; 'to:addr:python-list': 0.38; 'aspects': 0.39; 'itself': 0.39; 'sure': 0.39; 'to:addr:python.org': 0.39; 'from:no real name:2**0': 0.61; 'affect': 0.61; 'course': 0.61; 'making': 0.63; 'header:Message-Id:1': 0.63; 'act': 0.63; 'name': 0.63; 'teaching': 0.64; 'great': 0.65; 'to:addr:aol.com': 0.68; 'overall': 0.69; 'as:': 0.81; 'subject:this': 0.83; "'and'": 0.84; "'for'": 0.84; 'concept.': 0.84; 'received:64.12.224': 0.84; 'costs,': 0.91; 'taught': 0.96 To: python-list@python.org, jimjhb@aol.com Subject: Is this PEP-able? fwhile X-MB-Message-Source: WebUI X-MB-Message-Type: User MIME-Version: 1.0 From: jimjhb@aol.com Content-Type: multipart/alternative; boundary="--------MB_8D03F2B8CFA6D42_1864_56DC1_webmail-m103.sysops.aol.com" X-Mailer: AOL Webmail 37834-STANDARD X-Originating-IP: [208.67.228.35] Date: Mon, 24 Jun 2013 15:52:54 -0400 (EDT) x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1372103575; bh=owbZ0NacWtoLApQRAJgxZh6Zqmnl5IWOCm77pmb7oe4=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=Gw8SSyEV1hY2nqWEi4N+MK+e05FQzoh85ULTFyHOeaVeIbixk4CahR9A/J7F/a4xU ad0yKWTwrPk/669XRtqlIWArskUq9t1gXC0whxnzDjT/ZyH9cg19OIdxnuuHX68rxW 87B1hQXo/I9FNGqwN+udcrWffrpc61dsGCiYoS6E= X-AOL-SCOLL-SCORE: 0:2:313412960:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d294b51c8a3967f01 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: 160 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1372103911 news.xs4all.nl 15989 [2001:888:2000:d::a6]:53176 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:49070 This is a multi-part message in MIME format. ----------MB_8D03F2B8CFA6D42_1864_56DC1_webmail-m103.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" Syntax: fwhile X in ListY and conditionZ: The following would actually exactly as: for X in ListY: fwhile X in ListY and True: fwhile would act much like 'for', but would stop if the condition after the= 'and' is no longer True. The motivation is to be able to make use of all the great aspects of the py= thon 'for' (no indexing or explict end condition check, etc.) and at the same time avoiding a 'break' from the= 'for'. =20 (NOTE: Many people are being taught to avoid 'break' and 'continue' at all= costs, so they instead convert the clean 'for' into a less-clean 'while'. Or they just let the 'for' run = out. You can argue against this teaching (at least for Python) but that doesn't mean it's not prevalent and prevaili= ng.) [People who avoid the 'break' by functionalizing an inner portion of the lo= op are just kidding themselves and making their own code worse, IMO.] I'm not super familiar with CPython, but I'm pretty sure I could get this u= p and working without too much effort. The mandatory 'and' makes sense because 'or' would hold the end value valid= (weird) and not accomplish much. The condition itself could of course have multiple parts to it, including '= or's. It's possible the name 'fwhile' is not optimal, but that shouldn't affect t= he overall merit/non-merit of the concept. Comments and Questions welcome. Thanks. =20 ----------MB_8D03F2B8CFA6D42_1864_56DC1_webmail-m103.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="us-ascii"
Syntax:

fwhile X in ListY and conditionZ:

The following would actually exactly as:=  for X in ListY:

fwhile X in ListY and True:

fwhile would act much like 'for', but wo= uld stop if the condition after the 'and' is no longer True.

The motivation is to be able to make use of all the gr= eat aspects of the python 'for' (no indexing or explict
end condition check, etc.) and at the sa= me time avoiding a 'break' from the 'for'.  

(NOTE:  Man= y people are being taught to avoid 'break' and 'continue' at all costs, so = they instead convert
the clean 'for' into a less-clean 'while'.  Or they just let the= 'for' run out.  You can argue against this teaching
(at least for Python) but that doesn't mean it's not prevalent and pr= evailing.)

[People who avoid the 'break' by functionalizing an inner portion of = the loop are just kidding themselves and making
their own code worse, IMO.]

I'm not super familiar with CPython, but I'm pretty sure I could get = this up and working without too much effort.
The mandatory 'and' makes sense because 'or' would hold the end value= valid (weird) and not accomplish much.
The condition itself could of course have multiple parts to it, inclu= ding 'or's.

It's possible the name 'fwhile' is not optimal, but that shouldn't af= fect the overall merit/non-merit of the concept.

Comments and Questions welcome.

Thanks.  
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