It should be noted that in R, environments are simply pointers. They take up no memory and shouldn't cause drastic slowdowns (I don't think).
On Wednesday, July 8, 2015 at 3:48:08 PM UTC-4, Brandon Taylor wrote: > > For example, here's a code snippet from R: > > function (x, data) eval(x$expr, data, x$env) > > x is an expression which contains an environment attribute. It is > evaluated first checking the bindings in data (data being a dataframe) and > then checing the bindings in x's environment. > > On Wednesday, July 8, 2015 at 3:37:04 PM UTC-4, Brandon Taylor wrote: >> >> *reifying. Deifying environments might not be the best idea. >> >> On Wednesday, July 8, 2015 at 3:34:53 PM UTC-4, Brandon Taylor wrote: >>> >>> I was aware of those packages (though I hadn't read the discussions >>> referenced). Macros are great but they are incredibly difficult to reason >>> with concerning issues of scope (at least for me). Deifying environments >>> could solve all of these issues (and so much more) in one fell swoop. >>> >>> On Wednesday, July 8, 2015 at 3:20:00 PM UTC-4, David Gold wrote: >>>> >>>> Some of these issues have been thought about fairly extensively by the >>>> stats community in particular, precisely on account of the use cases you >>>> cite: >>>> >>>> https://github.com/JuliaStats/DataFrames.jl/pull/472 >>>> https://github.com/JuliaStats/DataFrames.jl/issues/504 >>>> <https://www.google.com/url?q=https%3A%2F%2Fgithub.com%2FJuliaStats%2FDataFrames.jl%2Fissues%2F504&sa=D&sntz=1&usg=AFQjCNHgUEZP8TyJ_BuUyyFA5SIxneOJTA> >>>> >>>> I think that the matter is still very much an open question. I have no >>>> sense that anything is going to be added to Base Julia itself. Currently, >>>> the best way (that I know of, anyway) to achieve the delayed evaluation >>>> effect is via the use of macros. See for instance: >>>> >>>> https://github.com/JuliaStats/DataFramesMeta.jl >>>> https://github.com/one-more-minute/Lazy.jl >>>> >>>> I'm hope somebody else will be able to pop in an give a more thorough >>>> answer, but the above may at least be a place to start. >>>> >>>> On Wednesday, July 8, 2015 at 2:03:45 PM UTC-4, Brandon Taylor wrote: >>>>> >>>>> Hadley Wickham's lazyeval package in R is pretty cool in that you can >>>>> attach an environment to an expression, pass it in and out of functions >>>>> with various modifications, and then evaluate the expression within the >>>>> original environment (or any other environment that you choose). R in >>>>> general has the functions like list2env and list(environment()) that >>>>> allow >>>>> one to convert an environment into a list and back again (list being the >>>>> R >>>>> equivalent of a Dict). Are there any plans to add these kind of features >>>>> to >>>>> Julia? >>>>> >>>>
