beginning of copy()

src/TimeDataFrames.jl

@@ -85,7 +85,56 @@ Base.view(df::TimeDataFrame, idx::CartesianIndex{2}) = view(df, idx[1], idx[2])
 Base.setindex!(df::TimeDataFrame, val, idx::CartesianIndex{2}) =
     (df[idx[1], idx[2]] = val)
 
-Base.broadcastable(df::TimeDataFrame) = df
+Base.broadcastable(tdf::TimeDataFrame) = tdf
+struct TimeDataFrameStyle <: Base.Broadcast.BroadcastStyle end
+
+Base.Broadcast.BroadcastStyle(::Type{<:TimeDataFrame}) =
+    TimeDataFrameStyle()
+
+Base.Broadcast.BroadcastStyle(::TimeDataFrameStyle, ::Base.Broadcast.BroadcastStyle) = TimeDataFrameStyle()
+Base.Broadcast.BroadcastStyle(::Base.Broadcast.BroadcastStyle, ::TimeDataFrameStyle) = TimeDataFrameStyle()
+Base.Broadcast.BroadcastStyle(::TimeDataFrameStyle, ::TimeDataFrameStyle) = TimeDataFrameStyle()
+
+function Base.copy(bc::Base.Broadcast.Broadcasted{TimeDataFrameStyle})
+    ndim = length(axes(bc))
+    if ndim != 2
+        throw(DimensionMismatch("cannot broadcast a time data frame into $ndim dimensions"))
+    end
+
+    data 
+    bcf = Base.Broadcast.flatten(bc)
+    colnames = unique!([_names(df) for df in bcf.args if df isa AbstractDataFrame])
+    if length(colnames) != 1
+        wrongnames = setdiff(union(colnames...), intersect(colnames...))
+        if isempty(wrongnames)
+            throw(ArgumentError("Column names in broadcasted data frames " *
+                                "must have the same order"))
+        else
+            msg = join(wrongnames, ", ", " and ")
+            throw(ArgumentError("Column names in broadcasted data frames must match. " *
+                                "Non matching column names are $msg"))
+        end
+    end
+    nrows = length(axes(bcf)[1])
+    df = DataFrame()
+    for i in axes(bcf)[2]
+        if nrows == 0
+            col = Any[]
+        else
+            bcf′ = getcolbc(bcf, i)
+            v1 = bcf′[CartesianIndex(1, i)]
+            startcol = similar(Vector{typeof(v1)}, nrows)
+            startcol[1] = v1
+            col = copyto_widen!(startcol, bcf′, 2, i)
+        end
+        df[!, colnames[1][i]] = col
+    end
+    return df
+end
+
+
+
+
 Base.ndims(::TimeDataFrame) = 2
 Base.ndims(::Type{<:TimeDataFrame}) = 2
 index(df::TimeDataFrame) = getfield(getfield(df, :data), :colindex)