On Fri, 2015-03-27 at 19:46, [email protected] wrote:
> Ok, I narrowed it down to a very small test case. The mymodule.jl file is
> at the bottom of this posting. If you save that to a file then run this
> code, you'll get the same effect as my original problem except with the
> 'index' method.
>
> using mymodule
>
> mydf = MyDataFrame(Any[], Index())
>
> # This line complains that `index` has no method matching
> index(::MyDataFrame)
This line is not valid syntax:
julia> # This line complains that `index` has no method matching
index(::MyDataFrame)
ERROR: syntax: invalid "::" syntax
So, correcting this everything seems to work, right?
> display(mydf)
>
> # This displays my `index` method
> methods(index)
>
> # This shows that my `index` method works
> index(mydf)
>
>
> === mymodule.jl ===
>
> module mymodule
>
> import DataFrames: AbstractDataFrame, DataFrame, Index, nrow, ncol
> import DataArrays: DataArray
>
> export MyDataFrame, nrow, ncol, Index, index, columns
>
> type MyDataFrame <: AbstractDataFrame
> columns::Vector{Any}
> colindex::Index
>
> function MyDataFrame(columns::Vector{Any}, colindex::Index)
>
> ncols = length(columns)
> if ncols > 1
> nrows = length(columns[1])
> equallengths = true
> for i in 2:ncols
> equallengths &= length(columns[i]) == nrows
> end
> if !equallengths
> msg = "All columns in a DataFrame must be the same length"
> throw(ArgumentError(msg))
> end
> end
>
> if length(colindex) != ncols
> msg = "Columns and column index must be the same length"
> throw(ArgumentError(msg))
> end
>
> new(columns, colindex)
> end
>
> end
>
> index(df::MyDataFrame) = df.colindex
> columns(df::MyDataFrame) = df.columns
>
> nrow(df::MyDataFrame) = ncol(df) > 0 ? length(df.columns[1])::Int : 0
> ncol(df::MyDataFrame) = length(index(df))
>
> end
>
> ==================
