RE: Re: Best practice for naming of options

*To*: mathgroup at smc.vnet.net*Subject*: [mg71551] RE: [mg71522] Re: Best practice for naming of options*From*: "Virgilio, Vincent - SSD" <Vincent.Virgilio at itt.com>*Date*: Wed, 22 Nov 2006 05:22:31 -0500 (EST)

Andrew, I have also wondered about best practices here. I decided to use full context names when there were shadows or other chance of conflict. Once, this forced me to think some about name lookup in Mathematica. I wondered if future versions of Mathematica could expand their name-lookup abilities along the lines of . . . C++. Here is a brief tutorial on C++ name lookup: http://h21007.www2.hp.com/dspp/tech/tech_TechDocumentDetailPage_IDX/1,17 01,990,00.html If this were applied to Mathematica, perhaps expression heads could imply the scope of their contexts. Then those contexts would have name-lookup priority during evaluation of subexpressions (of the expression head). Could this solve the option-name problem? Full context names would still resolve shadows, but I think would be required much less frequently (for those of us who use them). Such additions could become breaking or silent changes to the Mathematica language. They could also lead to surprising behavior. I can't say either way---it would require an expert's judgement, and some field trials. Vince Virgilio -----Original Message----- From: Philipp [mailto:Philipp.M.O at gmail.com] Sent: Tuesday, November 21, 2006 7:05 AM To: mathgroup at smc.vnet.net Subject: [mg71551] [mg71522] Re: Best practice for naming of options David, I think you're missing the point a bit. MySpaceScaleFunction type symbol names for options are fine until (as Andrew points out) someone writes a package with a symbol that has exactly the same name (hey, you came with it, so could anyone else). Making the name longer only decreases the probability of conflict, it does not remove it. Andrew is asking for a methodology to avoid conflicts between "packaged" symbols. I don't have an answer, the only heuristic I can offer is "When in doubt, use full context names for symbols". Cheers Philipp David Park wrote: > Andrew, > > What is wrong with using a name like MySpaceScaleFunction, or assuming > that the option is actually associated with some function Foo, FooScaleFunction? > You say that it produces cumbersome option names but if you have a > usage message for it one can then use command completion Ctrl-K to > bring up the options or routines that start with Foo say. So it is not > all that cumbersome, and having longer specific names vastly cuts down > on the possibility of conflicts. In my opinion, longer specific names > are much better than short ambiguous names. > > David Park > djmp at earthlink.net > http://home.earthlink.net/~djmp/ > > From: Andrew Moylan [mailto:andrew.j.moylan at gmail.com] > > Hi all, > > When writing my own functions that use options, I sometimes have a > problem where option names become shadowed by other packages that are > loaded later. For example, I might want to use an option called > ScaleFunction: > > BeginPackage["MySpace`"]; > ScaleFunction::"usage" = "hello"; > EndPackage[]; > > Needs["Graphics`"] > > Now the name ScaleFunction is shadowed by the option of the same name > from the Graphics package: > > Evaluating > ? ScaleFunction > gives > Graphics`Common`GraphicsCommon`ScaleFunction > > I can think of two possible solutions to this problem, each with a > different problem: > > (1) I could try to always choose unique names for my options. This > produces cumbersome option names and in any case only works until I or > someone else writes a package with that option name. > > (2) I could use _strings_ for option names instead of symbols: > Func["ScaleFunction" -> x] instead of Func[ScaleFunction -> x]. I have > seen this done sometimes in the built-in Mathematica functions. > Unfortunately, with this approach it no longer becomes possible to > define usage text for options in the usual way: > > "ScaleFunction"::usage = "ScaleFunction is an option to Func that > ..."; gives the warning > Message::name : Message name ScaleFunction::usage is not of the form > \ symbol::name or symbol::name::language. > > Is there a way to get the best of both worlds (define usage strings > AND ensure that option names don't become shadowed)? > > Cheers, > Andrew > > P.S. I observe that the built-in function NSum has an option called > NSumTerms. I think this option would be better called Terms. Could it > be that the writers of that function faced the same dilemma that I am > facing? ************************************ This e-mail and any files transmitted with it are proprietary and intended solely for the use of the individual or entity to whom they are addressed. If you have received this e-mail in error please notify the sender. Please note that any views or opinions presented in this e-mail are solely those of the author and do not necessarily represent those of ITT, Inc. The recipient should check this e-mail and any attachments for the presence of viruses. ITT accepts no liability for any damage caused by any virus transmitted by this e-mail. ************************************