On Sun, 08 Nov 2009 09:33:39 -0500 Mehmet Erol Sanliturk <sanlit...@ttmail.com> wrote:
> Marco van de Voort wrote: > > On Sun, Nov 08, 2009 at 12:17:35AM +0000, Howard Page-Clark wrote: > >>>> On Sat, 7 Nov 2009, Marco van de Voort wrote: > >>>>> This is not orthogonal. VAR parameters are generally updated > >>>>> instantaniously. By delaying the update over a temp variable you break > >>>>> another aspect of the VAR parameter. > >> I don't understand 'not orthogonal' in this sentence. What meaning does > >> orthogonal have apart from 'being at right angles to' ? > > > > I'm not entirely sure where the phrase comes from (see also Mehmet), but I > > guess it has something to do with the axises in a Carthesian coordinate > > system, and from there dimensions (point,length,area,volume etc). > > A translation along one axis doesn't change the other in classic geometry. > > > > Assume it came to indicate absence of side-effects from there. > > If you search > > orthogonality in programming language design > > in www.yahoo.com , you may find many references , such as > > > > http://en.wikipedia.org/wiki/Programming_language_design > http://en.wikipedia.org/wiki/Orthogonality_(programming) > > Design Criteria for a Language : > http://www.ist.rit.edu/~jdb/plc/wk1.pdf > > Orthogonality in Language Design - Why and how to fake it : > http://prog.vub.ac.be/~wdmeuter/PostJava/Herrmann.pdf > > Compactness and Orthogonality : > http://catb.org/esr/writings/taoup/html/ch04s02.html > > On orthogonality in programming languages : > http://portal.acm.org/citation.cfm?id=954246&dl=ACM&coll=portal&CFID=934114&CFTOKEN=43879943 > > > The Art of Unix Programming : > ( To design for compactness and orthogonality ... ) > http://www.linuxtopia.org/online_books/programming_books/art_of_unix_programming/ch04s02_4.html > > > > among many others . > > > Abundance of references show that orthogonality is a widely considered > concept in programming language design . > > As an example , the following statements are not orthogonal to each other : > > ( 1 ) if - go to > ( 2 ) for > ( 3 ) repeat > ( 4 ) while > ( 5 ) case > > because any one of them may be expressed by the others , but > > ( 1 ) go to > ( 2 ) := ( assignment ) > > are orthogonal because it is not possible to express any one of them by > the other . Thanks guys for your explanations. -- _______________________________________________ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
