Yes thats true but thats the future and currently not in stable Julia.
Am Samstag, 30. Mai 2015 12:39:10 UTC+2 schrieb Jiahao Chen: > > For this use case of optionally present data, Nullable would seem > appropriate (although this is 0.4-only). > > > http://julia.readthedocs.org/en/latest/manual/types/#nullable-types-representing-missing-values > > Thanks, > > Jiahao Chen > Research Scientist > MIT CSAIL > > On Sat, May 30, 2015 at 2:08 PM, Tobias Knopp <tobias...@googlemail.com > <javascript:>> wrote: > >> There is one exception though, which is keyword arguments >> >> >> Am Samstag, 30. Mai 2015 03:49:45 UTC+2 schrieb Steven G. Johnson: >>> >>> *No!* This is one of the most common misconceptions about Julia >>> programming. >>> >>> The type declarations in function arguments have *no impact* on >>> performance. Zero. Nada. Zip. You *don't have to declare a type at >>> all* in the function argument, and it *still* won't matter for >>> performance. >>> >>> The argument types are just a filter for when the function is applicable. >>> >>> The first time a function is called, a specialized version is compiled >>> for the types of the arguments that you pass it. Subsequently, when you >>> call it with arguments of the same type, the specialized version is called. >>> >>> Note also that a default argument foo(x, y=false) is exactly equivalent >>> to defining >>> >>> foo(x,y) = ... >>> foo(x) = foo(x, false) >>> >>> So, if you call foo(x, [1,2,3]), it calls a version of foo(x,y) >>> specialized for an Array{Int} in the second argument. The existence of a >>> version of foo specialized for a boolean y is irrelevant. >>> >> >
