Ah yeah that works! The wikibooks documentation is wrong then, maybe i'll correct it:
http://en.wikibooks.org/wiki/Introducing_Julia/Dictionaries_and_sets On Thursday, May 14, 2015 at 4:08:45 PM UTC-4, Peter Brady wrote: > > I believe you want > > d[:d] = 2 > > Peter. > > On Thursday, May 14, 2015 at 1:25:58 PM UTC-6, Edward Chen wrote: >> >> To whom it may concern: >> >> I am having trouble adding elements to my dictionary and then passing it >> into a function: >> >> function f(;kw...) >> for (k,v) in kw >> println(k,",",v) >> end >> end >> d = {:a => 1, :b => "c"} # this works >> # d = Dict() # but this line >> # d["d"] = 2 # with this fails >> f(;d...) >> >> Thanks, >> Ed >> >> On Tuesday, October 15, 2013 at 9:46:17 PM UTC-4, Jeff Bezanson wrote: >>> >>> Although converting a string to a symbol is reasonably efficient, it's >>> too much extra work to do for something like a function call where every >>> cycle counts. You could easily end up doing this work repeatedly, for each >>> one of many calls. It also might lead somebody to think strings are equally >>> valid in this context, and use them exclusively, which I would consider a >>> performance trap. >>> On Aug 7, 2013 3:04 PM, "Westley Hennigh" <westley...@gmail.com> wrote: >>> >>>> I think the issue is transparency for the user. If they have a >>>> dictionary and get an error when they call (I kind of like Elliot's >>>> name) `dictsplat()`, it's pretty obvious what the problem is. If they just >>>> use the dictionary of strings and we do the conversion for them it might >>>> not be as clear. >>>> >>>> On Wednesday, August 7, 2013 12:55:42 AM UTC-7, Ivar Nesje wrote: >>>>> >>>>> What is the problem with having minus or space in a symbol? You'd have >>>>> to generate the code using Expr() and symbol("var-with minus&space"), as >>>>> the parser uses those characters as delimiters when it parses code. >>>>> Errors >>>>> should be given when you use a dictionary with keys that does not match >>>>> the >>>>> keyword arguments of the function, so there is no reason to give a >>>>> different error if some of the characters should be invalid. >>>>> >>>>> Ivar >>>>> >>>>> kl. 07:40:50 UTC+2 tirsdag 6. august 2013 skrev Elliot Saba følgende: >>>>>> >>>>>> One of the problems with this is that strings have quite a bit more >>>>>> leeway in what they can contain than symbols. What happens if your >>>>>> strings >>>>>> have spaces? Or minus symbols? Getting an error from the `symbol()` >>>>>> function while trying to splat a dictionary seems like it might be >>>>>> confusing. >>>>>> >>>>>> If doing this conversion automatically wouldn't take too much cpu >>>>>> time, then doing it manually won't take too much cpu time either. :) >>>>>> It >>>>>> should be pretty straightfoward to write e.g. a `dictsplat()` function >>>>>> that >>>>>> converts any string keys to symbols, and throws a meaningful error if >>>>>> they >>>>>> are unable to do so. >>>>>> >>>>>> >>>>>> On Mon, Aug 5, 2013 at 6:38 PM, Westley Hennigh <westley...@gmail.com >>>>>> > wrote: >>>>>> >>>>>>> Hmm, maybe it is. I'm a partial judge. >>>>>>> >>>>>>> But just to be clear: I don't want to actually modify the dict or >>>>>>> pursue this if it will be considerably slower. >>>>>>> >>>>>>> I do think it's fairly unambiguous. And if you pulled a dictionary >>>>>>> out of some json and wanted to use it as parameters, I think this would >>>>>>> seem pretty straightforward / convenient. >>>>>>> >>>>>>> On Monday, August 5, 2013 6:08:12 PM UTC-7, Jacob Quinn wrote: >>>>>>>> >>>>>>>> Auto-converting strings to symbols in this case seems pretty >>>>>>>> auto-magical (in a bad way). I would just expect the user to call the >>>>>>>> symbol(x) call themselves before passing them in. >>>>>>>> >>>>>>>> -Jacob >>>>>>>> >>>>>>>> >>>>>>>> On Monday, August 5, 2013 8:01:56 PM UTC-5, Westley Hennigh wrote: >>>>>>>>> >>>>>>>>> Ok, I have -perhaps- a slightly more interesting question based on >>>>>>>>> this. >>>>>>>>> >>>>>>>>> In your above example, suppose you have a dict `d = {"x" => 3, "y" >>>>>>>>> => 4}`. Note the strings. >>>>>>>>> If you called your function f with said dict, I think (could be >>>>>>>>> wrong) that what you're after is pretty unambiguous (to treat the >>>>>>>>> strings >>>>>>>>> as symbols). What's more, I think that the conversion between strings >>>>>>>>> and >>>>>>>>> symbols can be pretty cheap. >>>>>>>>> >>>>>>>>> So maybe we could add support for more efficiently calling >>>>>>>>> functions with dictionaries of strings of named args (without >>>>>>>>> generating >>>>>>>>> one containing symbols). >>>>>>>>> >>>>>>>>> I see line 429 in https://github.com/JuliaLang/julia/blob/master/ >>>>>>>>> src/julia-syntax.scm, I think dictionaries are being expanded >>>>>>>>> around like 1670 and then passed as an unsorted list. So maybe this >>>>>>>>> wouldn't be more efficient... Not sure, are you more familiar with >>>>>>>>> this >>>>>>>>> code? >>>>>>>>> >>>>>>>>> >>>>>>>>> On Monday, August 5, 2013 5:14:02 PM UTC-7, Westley Hennigh wrote: >>>>>>>>>> >>>>>>>>>> Lol. I apologize for taking your time, thanks! >>>>>>>>>> >>>>>>>>>> On Monday, August 5, 2013 5:08:45 PM UTC-7, Mike Nolta wrote: >>>>>>>>>>> >>>>>>>>>>> ``` >>>>>>>>>>> julia> f(;x=0,y=0) = (x,y) >>>>>>>>>>> # methods for generic function f >>>>>>>>>>> f() at none:1 >>>>>>>>>>> >>>>>>>>>>> julia> d = {:x => 3, :y => 4} >>>>>>>>>>> {:y=>4,:x=>3} >>>>>>>>>>> >>>>>>>>>>> julia> f(;d...) >>>>>>>>>>> (3,4) >>>>>>>>>>> ``` >>>>>>>>>>> >>>>>>>>>>> -Mike >>>>>>>>>>> >>>>>>>>>>> On Mon, Aug 5, 2013 at 8:02 PM, Westley Hennigh >>>>>>>>>>> <westley...@gmail.com> wrote: >>>>>>>>>>> > Heh, ya, but I can always pass a dictionary. It would be sweet >>>>>>>>>>> if the names >>>>>>>>>>> > could be broken out so that you can read the defaults and we >>>>>>>>>>> don't end up >>>>>>>>>>> > with big blocks of `get(args, thing, default)` at the top of >>>>>>>>>>> functions. >>>>>>>>>>> > >>>>>>>>>>> > On Monday, August 5, 2013 4:53:55 PM UTC-7, Mike Nolta wrote: >>>>>>>>>>> >> >>>>>>>>>>> >> ``` >>>>>>>>>>> >> julia> f(;kw...) = for (k,v) in kw; println(k,",",v); end >>>>>>>>>>> >> # methods for generic function f >>>>>>>>>>> >> f() at none:1 >>>>>>>>>>> >> >>>>>>>>>>> >> julia> d = {:a => 1, :b => "c"} >>>>>>>>>>> >> {:b=>"c",:a=>1} >>>>>>>>>>> >> >>>>>>>>>>> >> julia> f(;d...) >>>>>>>>>>> >> b,c >>>>>>>>>>> >> a,1 >>>>>>>>>>> >> ``` >>>>>>>>>>> >> >>>>>>>>>>> >> -Mike >>>>>>>>>>> >> >>>>>>>>>>> >> On Mon, Aug 5, 2013 at 7:17 PM, Westley Hennigh >>>>>>>>>>> >> <westley...@gmail.com> wrote: >>>>>>>>>>> >> > I hope I'm being dense and that this already exists. >>>>>>>>>>> >> > >>>>>>>>>>> >> > I have some pre-named-args julia which -effectively- >>>>>>>>>>> flattens a >>>>>>>>>>> >> > dictionary >>>>>>>>>>> >> > of named things into an ordered tuple of args that are >>>>>>>>>>> passed into a >>>>>>>>>>> >> > function. I'd really like to just use the dictionary as a >>>>>>>>>>> set of named >>>>>>>>>>> >> > args. >>>>>>>>>>> >> > Is that possible? >>>>>>>>>>> >>>>>>>>>> >>>>>>
