Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.glorb.com!usenet.stanford.edu!news.iecc.com!.POSTED!nerds-end From: "robin" Newsgroups: comp.compilers Subject: Re: Programming language and IDE design Date: Mon, 25 Nov 2013 10:33:43 +1100 Organization: Compilers Central Lines: 21 Sender: johnl@iecc.com Approved: comp.compilers@iecc.com Message-ID: <13-11-031@comp.compilers> References: <13-11-016@comp.compilers> <13-11-018@comp.compilers> NNTP-Posting-Host: news.iecc.com Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Trace: leila.iecc.com 1385568911 5124 64.57.183.58 (27 Nov 2013 16:15:11 GMT) X-Complaints-To: abuse@iecc.com NNTP-Posting-Date: Wed, 27 Nov 2013 16:15:11 +0000 (UTC) Keywords: Fortran, parse Posted-Date: 27 Nov 2013 11:15:11 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:1055 From: "George Neuner" Sent: Tuesday, November 19, 2013 11:02 AM > AFAIK, Fortran's DO loop requires the most lookahead of any of the > classic language features: LL(4) [if I'm counting correctly]. > > 10DOI=42 > 10DOI=42,45 The statements are DO 10 I = 42 DO 10 I = 42, 45 > Card Fortran didn't require whitespace separation. Still doesn't, though since the advent of Fortran 90, an alternative free source form requires a space between the syntactic elements, so the difficulty doesn't arise. Nor, can the "classic" (apocryphal?) error DO10I=42.45 occur (assuming that declarations are made compulsory with the statement IMPLICIT NONE).