mdcfrancis
Joins are always n-way merge joins, so you can write something like y = 2x^2 - 3z + c and fold that into a single streaming operation y = f( x, z, c ) where y, x, z and c are time streams.
When rendered to screen they looked very similar to your examples. With plugins in the IDE you could directly plot and array of time series as a chart.
Since the time I wrote NamedTuples the Julia core team folded the functionality into the core of Julia https://docs.julialang.org/en/v1/manual/types/#Named-Tuple-T.... This is the core of https://juliadb.org/ all credit to the Julia core team
The cons, top three from the top of my head, implicit array concat ( going in 0.5 ), String types ( going soon ), anonymous function performance ( gone by 1.0 )
None of these are show stoppers, but they do sometimes fall into the category of surprising. The core dev are very aware of the issues and if you look at the road map for 1.0 many are either well on their way to being fixed or are scheduled to be resolved.
As a person who has spent the best part of year coding almost exclusively in Julia (I work in finance, we were one of the main sponsors of JuliaCon, though these are my personal thoughts) I want to chime in a little.
To get to 1.0 many of the cons in the language will be solved and there are plans in place for much of this.
I never cease to be surprised by the brevity of code to solve complex problems. Something which would be hundreds of lines in Java/C++ often turns into 50 or so lines of much more readable code.
When asked to describe Julia I struggle but end up this way 'I can make Julia 'dance' like no other fast programming language' though to be fair modern JS is pretty close for many tasks.
The parametric type system is to me the strongest part of the system - I describe it simply as 'templates that work', it is ridiculously powerful and (to me) is the most compelling reason to learn Julia.
I personally find even at 0.4 it is very usable even for tasks which are not math. Though the run time is currently fairly heavy.
So congrats to the Julia team.