Path: csiph.com!newsfeed.hal-mli.net!feeder3.hal-mli.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!newspeer1.nac.net!border4.nntp.dca.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!news.iecc.com!.POSTED!nerds-end From: glen herrmannsfeldt Newsgroups: comp.compilers Subject: Re: Programming language and IDE design Date: Fri, 8 Nov 2013 05:21:24 +0000 (UTC) Organization: Aioe.org NNTP Server Lines: 25 Sender: johnl@iecc.com Approved: comp.compilers@iecc.com Message-ID: <13-11-005@comp.compilers> References: <13-10-016@comp.compilers> <13-10-017@comp.compilers> <13-11-003@comp.compilers> NNTP-Posting-Host: news.iecc.com X-Trace: leila.iecc.com 1383945316 38114 64.57.183.58 (8 Nov 2013 21:15:16 GMT) X-Complaints-To: abuse@iecc.com NNTP-Posting-Date: Fri, 8 Nov 2013 21:15:16 +0000 (UTC) Keywords: design, tools Posted-Date: 08 Nov 2013 16:15:16 EST X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com Xref: csiph.com comp.compilers:1029 Martin Ward wrote: > BartC makes the point that the redundancy > provided by enforced consistency between grouping and indentation > will catch typos which would otherwise cause bugs in the code. (big snip) > This point raises some important issues about languages and compilers: (snip) > (2) Absolutely no behaviour should be "implementation dependent" > or "undefined". Every syntactically valid program should have > a single semantically valid meaning (even if that meaning > is "halt with an error message"). Much "implementation dependence" comes from dependence on the host processor. Maybe sometimes too much, but it is nice to be able to use the new features of newer processors. Many early machines were sign magnitude, but most now use twos complement, which mostly is an advantage. Different word sizes are also a common dependence, with 36 bit words and 6-bit characters common on the early scientific machines. -- glen