Interface for melting data.frame?

[benwhalley]

I'm aware of the other issues that have been raised on this, but am trying to understand the rationale for removing the ability to melt a data.frame entirely, rather than simply switching away from the reshape dependency.

I have previously (perhaps wrongly) taught students to use data.table::melt on data frames. I understand the motivation to move away from reshape, but rather than breaking old code, would it be possible to coerce dataframes to data.table and use the new routines, obviously issuing a warning to the user as it happens?

[MichaelChirico]

Thanks for raising. This one is a lot easier to do (than adding melt.list, melt.matrix, etc methods), and I think we should support it.

[jangorecki]

Agree, providing data.frame method to dispatch seems to be best way. This also means that loading reshape after data.table will make dispatch use reshape method.