implement getrows for RowTable and ColumnTable

src/Tables.jl

@@ -568,14 +568,15 @@ end
 """
     getrows(x, inds; view=nothing)
 
-Return one or more rows from table `x` according to the position(s) specified by `inds`.
+Return one or more rows from table `x` according to the position(s) specified by `inds`:
 
 - If `inds` is a single integer return a row object.
 - If `inds` is a collection of integers, return a table object. 
-  In this case,t he returned type is not necessarily the same as the original table type.
+  In this case, the returned type is not necessarily the same as the original table type.
 
 The `view` argument influences whether the returned object is a view of the original table
 or an independent copy:
+
 - If `view=nothing` (the default) then the implementation for a specific table type 
   is free to decide  whether to return a copy or a view.
 - If `view=true` then a view is returned and if `view=false` a copy is returned.

src/namedtuples.jl

@@ -106,6 +106,14 @@ function rowtable(itr::T) where {T}
     return collect(namedtupleiterator(eltype(r), r))
 end
 
+function getrows(x::RowTable, inds; view::Union{Bool,Nothing} = nothing)
+    if view === true
+        return view(x, inds)
+    else
+        return x[inds]
+    end
+end
+
 # NamedTuple of arrays of matching dimensionality
 const ColumnTable = NamedTuple{names, T} where {names, T <: NTuple{N, AbstractArray{S, D} where S}} where {N, D}
 rowcount(c::ColumnTable) = length(c) == 0 ? 0 : length(c[1])
@@ -173,3 +181,11 @@ function columntable(itr::T) where {T}
     return columntable(schema(cols), cols)
 end
 columntable(x::ColumnTable) = x
+
+function getrows(x::ColumnTable, inds; view::Union{Bool,Nothing} = nothing)
+    if view === true
+        return map(c -> view(c, inds), x)
+    else
+        return map(c -> c[inds], x)
+    end
+end