[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: XML design of ((a and b) or c)
Yes, boolean logic is as old as the hills, but the question here is whether the evaluation of AND and OR stopped once the value became determined, or whether they evaluated all arguments. If evaluation stops, then AND and OR can be used as control constructs. Leigh. -----Original Message----- From: Ken North [mailto:kennorth@s...] Sent: Thursday, December 14, 2006 1:34 PM To: xml-dev@l... Subject: Re: XML design of ((a and b) or c) >> It's possible that Lisp in 1958 had the AND/OR feature; [4] is a good >> read but doesn't give clear enough indication of Lisp prior to 1.5. >> >> Does anybody know of a language after Algol 58 and before Lisp 1.5 that >> had this feature? Keep in mind AND gates and OR gates were fundamental computer circuitry, just like adder circuits, timing circuits and registers. So there were machine language and assembly language programmers using AND and OR instructions of various flavors. As for compiled languages, both FORTRAN and COBOL had keywords for AND and OR logic. Grace Hopper developed FLOWMATIC for Univac in the 1950s, which fed into the COBOL standard. I don't know about FLOWMATIC, but COBOL had/has 'AND' and 'OR' keywords. Grace Hooper and the Univac I are shown in this 1952 photo at the Computer History timeline of software and languages: http://www.computerhistory.org/timeline/?category=sl Another language that emerged in the 1950s was FORTRAN. FORTRAN has logical statements with .AND. and .OR. logical operators, but I don't know precisely what year they became part of the language. My old FORTRAN reference manual sits in the Computer History Museum. It was FORTRAN IV (vintage 1964), when FORTRAN included .AND. and .OR. operators. An earlier version (FORTRAN II) apparently didn't have .AND. and .OR. This is an IBM 704 FORTRAN reference manual from 1958: http://www.bitsavers.org/pdf/ibm/704/C28-6000-2_704_FORTRANII.pdf This photo of the IBM 709 computer is vintage 1957. http://www-03.ibm.com/ibm/history/exhibits/mainframe/mainframe_2423PH709 .html This reference manual for the IBM 709 explains the machine instruction set, including AND and OR instructions. It also includes an IBM 709 FORTRAN reference. http://www.bitsavers.org/pdf/ibm/709/709_RefMan_Fortran.pdf ======== Ken North =========== www.WebServicesSummit.com www.SQLSummit.com www.GridSummit.com _______________________________________________________________________ XML-DEV is a publicly archived, unmoderated list hosted by OASIS to support XML implementation and development. To minimize spam in the archives, you must subscribe before posting. [Un]Subscribe/change address: http://www.oasis-open.org/mlmanage/ Or unsubscribe: xml-dev-unsubscribe@l... subscribe: xml-dev-subscribe@l... List archive: http://lists.xml.org/archives/xml-dev/ List Guidelines: http://www.oasis-open.org/maillists/guidelines.php
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] |
PURCHASE STYLUS STUDIO ONLINE TODAY!Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced! Download The World's Best XML IDE!Accelerate XML development with our award-winning XML IDE - Download a free trial today! Subscribe in XML format
|