Super late to the party here. But this is an interesting side effect of how julia handles composite types.
If you initialize a variable inside the type definition block it won't get added as a field to the type, but it still gets stored in memory that can be accessed by any inner constructors. For example: type myTyp id counter = 0 myTyp() = new(counter+=1) end a = myTyp(); #outputs a myTyp instance with id=1 b = myTyp(); #outputs a myTyp instance with id=2 b = myTyp(); #outputs a myTyp instance with id=3... The behavior is similar to how class static variables behave in oo languages. On Saturday, December 21, 2013 at 4:37:10 AM UTC-5, Marcus wrote: > > I am a little confused about constructing composite types. Given the > definition > > type MyType > x::Int > y::Int = 6 > MyType() = new() > end > > an instance of MyType can be created using > > m = MyType() > > At that point, m.x acts as expected --- I can assign to it, read its > value, and so forth. However, attempting to access m.y produces an error > that MyType has no field y. Based on another post, I gather that my attempt > to provide a value to m.y in this manner is not allowed If that's the case, > what exactly is the effect of "y::Int = 6" If this part of the code is > completely ignored, it would be really nice if the system let me know since > initializing fields in this way is common in many languages. > > Also, I gather that a workaround is to use a constructor that takes named > arguments. Is that still the recommended way? With just two fields, things > are not difficult, but if the type has 20, calling a constructor with 20 > positional arguments would be difficult. > > >
