[GSoC] Dataframes for D

[jmh530]

On Thursday, 18 July 2019 at 05:03:38 UTC, Prateeek Nayak wrote:
> [snip]

Thanks for the update. I'm glad you're still making good progress.

I'm just looking over the readme.md. I noticed the "at" function 
has a signature like at!(row, column)(). Because it uses a 
template, doesn't that imply that the row and column parameters 
must be known at compile-time? What if we want run-time access 
using a function style instead of like df[0, 0]? mir's ndslice 
also has a set of select functions that are also useful for 
access.

There's also a typo in the GroupBy text:
"Group DataFrame based on na arbitrary number of columns."

I noticed that you make a lot of use of static foreach's over 
RowType in dataframe.d. Does that this means that this means 
there isn't any extra cost if you use a homogeneous dataframe 
with RowType.length == 1? If you can advertise that it doesn't 
have any additional overhead for working with homogeneous, then 
that's probably a win. You might also add a trait for 
isHomogeneous that checks if RowType.length == 1.