As we all know, there are certain characters which will do not show up properly in searches.

Some examples are:

f = b
f := b
f[x_, y__, ___] := c
a // f
g /@ {x, y, z}

I think it would be useful if we were to modify posts to contain not only the characters, but the name of the characters immediately afterward. For example if we had a question like this:

"What is /@ and what does it do?"

Clearly the person who asked it didn't know about it. It may be better then if we, collectively as a whole, stated in questions that talked of /@, to include the name of the operator. For example we may edit the question so it is phrased:

"What is /@ (Map operator) and what does it do?"

This simplifies any searches that may done as well. We still can't search for /@, but (hopefully) when people know what the operator name is, they can simply type in Map operator and see the posts related to this.

Furthermore, in questions that are tagged in relation to this we should use . For example, questions asking about /@ can be tagged: .

What are your thoughts on this? There's a lot of non-trivial functional operators and we need a systematic way of representing them on the site in an easily searchable and understandable way. I doubt many people read f /@ x for the first time and thought "This is mapping f onto the list x".

  • I think this is an excellent suggestion. Well worth investing some time to figure out the best approach here.
    – Andy Ross
    Commented Jan 19, 2012 at 2:04
  • @AndyRoss: Thanks. I do realize it will require the majority of people to agree on this, in addition to a everyone making an effort to watch out for these things. Lots of experienced users will say "Use map" or try "f /@ x" and may not realize that some people don't know one form or the other. Commented Jan 19, 2012 at 2:07
  • I think this does raise some valid points re: the searchability of operators. I don't think it deserves a separate tag, but certainly "map operator" could be added somewhere in the question body. I think if they're at the point where they recognize /@ as Map and look for the specific tag, they might as well look into the documentation center :) I would not be for a suggestion that uses this tag/uses descriptive text every time /@ is mentioned in the question or answer...
    – rm -rf Mod
    Commented Jan 19, 2012 at 2:08
  • @R.M: In that case, perhaps we should just tag those questions with functional-programming or list-processing, since usually those operators are used in those contexts. Commented Jan 19, 2012 at 2:09
  • @MikeBantegui Perhaps, if the intent is on the usage and applicability (or the right function from the /@-@@-@@@-//@-~, etc. family) then functional-programming might be apt.
    – rm -rf Mod
    Commented Jan 19, 2012 at 2:12
  • One of the problems with this is (and this isn't limited to Mathematica.SE or to Stack Exchange even) is that operators such as this have virtually zero organic search potential. I'm not saying that's not a reason not to do it, but it's only going to benefit those "in the know". However, for those that are in the know, it's a fantastic idea. If there was a way to somehow increase organic search potential as well, then even better. In other words, do it, but can we do better to increase searchability for those that do not know the symbols like the back of their hand?
    – casperOne
    Commented Jan 19, 2012 at 3:46
  • There is a special character search engine in development, listed at StackApps: SymbolHound
    – David Z
    Commented Jan 21, 2012 at 1:04

2 Answers 2


A possible shortcut that wouldn't be as involved would be to post a question whose answer is a nice list of useful operators along with some simple use cases. If it were listed as faq and had a nice number of upvotes it might serve the purpose.

In that vein, I would also suggest one for useful keyboard shortcuts.

  • I like this suggestion. I hadn't really thought of that and it may be the easiest and most straight forward option. You get the benefit that it would probably come up on Google. Commented Jan 19, 2012 at 2:13
  • 1
    I disagree, in that list/reference answers like this are typically frowned-upon on Stack Exchange sites; they are also danger signs for beta sites as well, as they usually fall under the "not constructive" banner on almost every Stack Exchange site. Granted, there are tons of examples where this is not applied in the wild, but a) few are actually classified as good content and b) beta sites will be judged on the quality of the questions asked on them. Best not to put an initial impression out there in this manner, IMO.
    – casperOne
    Commented Jan 19, 2012 at 3:44
  • @casperOne I'm starting to lean this way as well but for slightly different reasons. It seems to me that we are adding a lot of really good content to such questions but that it is information overload and might do more harm than good.
    – Andy Ross
    Commented Jan 19, 2012 at 3:57
  • I do not think this should be a question. I have put something like it in the tag wiki for syntax, although it is awaiting approval.
    – Verbeia
    Commented Jan 21, 2012 at 4:49

I have started a listing of these operators and special characters in the tag wiki for (awaiting approval).

I don't think that we should encourage questions such as "what is @@@ and what does it do?", because the answer is readily searchable in the Mathematica documentation from within Mathematica and in the web version of that documentation.

I agree that we need a tag for , but it shoudl be more about how to implement it -- for example, questions along the lines of "what is a functional programming alternative to this horrible set of nested Do[] loops?" -- than what the cat-sat-on-my-keyboard operators actually mean and do.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .