Hi,
I have implemented DataTable and a decent DSL to make SQL like queries on it
(where, select, order, group_by is supported). Table is represented as
tuple/object of columns, each column is seq of some type, usually primitive
type.
type
DataTable = concept x
x is tuple|object
for f in fields(x):
x is seq ## all columns should be of the same length
The definition is clear and simple, I am pretty happy with it. The names of
columns and types of columns are known at compile time, scheme is set in stone
at compile time.
Now, I want to define _ordered_ DataTable by one of the columns (think of Table
with set primary key). OrderedDataTable is a DataTable, this is the
relationship I want to maintain so all procs accepting DataTable should work on
OrderedDataTable as well. The key is simply the name of the column the table is
sorted on and it is known at _compile time_. Since key is known at compile
time, I though I can have it as _type tag_ only and keep binary representation
untouched.
Basically, I was leaning towards something like this
type
OrderedDataTable[key: static[string]] = concept of DataTable
# Not clear what to do with key to preserve it
OrderedDataTable is "type tagged" tuple, its binary representation **exactly**
the same as of untagged tuple, but type info contains extra string tag that I
can extract using getTypeInst() in macro or any other means.
Does it sound possible or reasonable?
