Add All and Between from IndexedTables.jl

Author: bkamins

src/DataAPI.jl

@@ -73,4 +73,23 @@ definition.
 """
 function describe end
 
+"""
+    Between(first, last)
+Select the columns between `first` and `last` from a table.
+"""
+struct Between{T1 <: Union{Int, Symbol}, T2 <: Union{Int, Symbol}}
+    first::T1
+    last::T2
+end
+
+"""
+    All(cols...)
+Select the union of the selections in `cols`. If `cols == ()`, select all columns.
+"""
+struct All{T}
+    cols::T
+end
+
+All(args...) = All(args)
+
 end # module