From -1216501457256077239 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,a69618ea97f65037 X-Google-Attributes: gidf78e5,public From: Andreas Rossberg Subject: Re: nested functions Date: 1998/04/23 Message-ID: <353F43D1.2781E494@ips.cs.tu-bs.de>#1/1 X-Deja-AN: 348251337 Content-Transfer-Encoding: 7bit Approved: stephen.clamage@sun.com (comp.std.c++) Sender: news@ips.cs.tu-bs.de (News Software) References: <6hac23$8lb$1@news2.isdnet.net> <353A6B2D.C2904893@concentric.net> Mime-Version: 1.0 Originator: clamage@taumet X-Nntp-Posting-Host: infbssts.ips.cs.tu-bs.de Content-Type: text/plain; charset=us-ascii Organization: TU Braunschweig, Abteilung Softwaretechnik Newsgroups: comp.std.c++ Bradd W. Szonye wrote: > > Nesting functions can be a useful scoping construct, but they add little > new utility or expressiveness to a language, so their absence is > generally not seen as a major failing of C or C++, except by advocates > of languages that do support function nesting. True nested functions (ie. closures) are a _very_ powerful feature that is absolutely essential if you're seriously using functionals (functions taking function(pointer)s as argument, also called higher-order functions). For example, would C++ have closures then the whole tedious business with iterators in the STL would be almost redundant, because you can factor out the most common kinds of iterations over arbitrary containers into a small set of simple library template functions like iterate, fold, map, etc. that do the looping for you (possibly in an optimized way) while you just supply the 'body' -- as a simple local function given directly. That's why programs in functional languages tend to be shorter by a factor of 10 than equivalent C/C++ code. A language with good support for higher-order functions and appropriate libraries highly increases productivity and modularity. So your statement is plainly false. -- Andreas Rossberg, rossberg_antispam@ips.cs.tu-bs.de Please remove the `_antispam' when replying via email. [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://reality.sgi.com/austern_mti/std-c++/faq.html ]