I suppose I should add that Julia doesn't really have a named tuple, the closest is an immutable constant type which is covered later in the manual.
On Monday, 5 January 2015 10:35:28 UTC, Sean Marshallsay wrote: > > Hi Ivo > > You're more than welcome to contribute to the documentation yourself > <https://github.com/JuliaLang/julia/blob/master/CONTRIBUTING.md#improving-documentation> > to > help clarify anything you found confusing. > > Regarding your second point, open() does not return a named type it > returns a tuple containing some kind of stream and some kind of process, > Pipe is some kind of stream and Process is some kind of process. Hopefully > the following code snippet will help clear things up. > > julia> x = open(`less`) > (Pipe(closed, 0 bytes waiting),Process(`less`, ProcessExited(0))) > > julia> y = typeof(x) > (Pipe,Process) > > julia> typeof(y) > (DataType,DataType) > > help?> issubtype > INFO: Loading help data... > Base.issubtype(type1, type2) > > True if and only if all values of "type1" are also of "type2". > Can also be written using the "<:" infix operator as "type1 <: > type2". > > julia> issubtype((Base.Pipe, Base.Process), (Base.AsyncStream, > Base.Process)) > true > > help?> super > Base.super(T::DataType) > > Return the supertype of DataType T > > julia> super(Base.Pipe) > AsyncStream > > julia> super(Base.Process) > Any > > So what we can see is that open() does return a (stream, process) tuple > but stream should actually be called AsyncStream and process should > actually be called Process. > > Hope this helps > Sean > > On Monday, 5 January 2015 06:59:31 UTC, ivo welch wrote: >> >> >> I am reading again about the type system, esp in >> http://julia.readthedocs.org/en/latest/manual/types/ . I am a good >> guinea pig for a manual, because I don't know too much. >> >> a tuple is like function arguments without the functions. so, >> >> mytuple=(1,"ab",(3,4),"5") >> >> is a tuple. good. >> >> what can I do with a typle? the manual tells me right upfront that I can >> do a typeof(mytuple) function call to see its types. good. >> >> alas, then it goes into intricacies of how types "sort-of" inherit. I >> need a few more basics first. >> >> I would suggest adding to the docs right after the typeof function that, >> e.g., mytuple[2] shows the contents of the second parameter. the julia cli >> prints the contents. the examples would be a little clearer, perhaps, if >> one used a nested tuple, like (1,2,("foo",3),"bar"). >> >> before getting into type relations, I would also add how one creates a >> named tuple. since open() does exactly this. well, maybe I am wrong. >> the docs say it returns a (stream,process), but typeof( open(`gzcat >> d.csv.gz`) tells me I have a (Pipe,Process). >> >> I know how to extract the n-th component of the open() returned tuple >> (with the [] index operator), but I don't know how to get its name. x.Pipe >> does not work for open(). >> >> well, my point is that it would be useful to add a few more examples and >> explanations here. >> >> regards, >> >> /iaw >> >>
