Add eachindex function (#151)

Author: eliascarv

src/tableselection.jl

@@ -42,7 +42,7 @@ Tables.rows(t::TableSelection) = SelectionRows(t)
 Tables.columnnames(t::TableSelection) = t.names
 
 function Tables.getcolumn(t::TableSelection, i::Int)
-  i > t.ncols && error("Table has no column with index $i.")
+  1 ≤ i ≤ t.ncols || error("Table has no column with index $i.")
   Tables.getcolumn(t.cols, t.mapnames[t.names[i]])
 end
 
@@ -100,6 +100,7 @@ Base.IteratorEltype(::Type{<:SelectionRow}) = Base.EltypeUnknown()
 # Indexing interface
 Base.firstindex(::SelectionRow) = 1
 Base.lastindex(row::SelectionRow) = row.ncols
+Base.eachindex(row::SelectionRow) = 1:row.ncols
 Base.getindex(row::SelectionRow, i::Int) = Tables.getcolumn(row, i)
 
 # Tables.jl row interface
@@ -134,14 +135,15 @@ end
 Base.iterate(s::SelectionRows, state::Int=1) =
   state > s.nrows ? nothing : (s[state], state + 1)
 
-Base.length(row::SelectionRows) = row.nrows
+Base.length(s::SelectionRows) = s.nrows
 Base.eltype(::Type{SelectionRows{T}}) where {T} = SelectionRow{T}
 Base.IteratorSize(::Type{<:SelectionRows}) = Base.HasLength()
 Base.IteratorEltype(::Type{<:SelectionRows}) = Base.HasEltype()
 
 # Indexing interface
 Base.firstindex(::SelectionRows) = 1
 Base.lastindex(s::SelectionRows) = s.nrows
+Base.eachindex(s::SelectionRows) = 1:s.nrows
 Base.getindex(s::SelectionRows, i::Int) = SelectionRow(s.selection, i)
 
 # Tables.jl interface

test/tableselection.jl

@@ -59,6 +59,7 @@
     s = TableTransforms.TableSelection(t, [:x, :y, :z], [:c, :d, :f])
     @test_throws ErrorException Tables.getcolumn(s, :c)
     @test_throws ErrorException Tables.getcolumn(s, 4)
+    @test_throws ErrorException Tables.getcolumn(s, -2)
   end
 
   @testset "SelectionRow" begin
@@ -95,7 +96,7 @@
       srow = TableTransforms.SelectionRow(s, i)
       @test firstindex(srow) == 1
       @test lastindex(srow)  == lastindex(row)
-      for j in eachindex(row)
+      for j in eachindex(srow)
         @test srow[j] == row[j]
       end
     end
@@ -139,7 +140,7 @@
     # Indexing interface
     @test firstindex(srows) == 1
     @test lastindex(srows)  == TableTransforms._nrows(s.cols)
-    for i in 1:length(srows)
+    for i in eachindex(srows)
       @test srows[i] == TableTransforms.SelectionRow(s, i)
     end
   end