Alakazam related

[ssnn]

Warning: class "tbl_df" is defined (with package slot ‘alakazam’) but no metadata object found to revise superClass information---not exported? Making a copy in package ‘shm’

Possible solution: http://stackoverflow.com/questions/28871632/how-to-resolve-warning-messages-metadata-object-not-found-spatiallinesnull-cla

But: - CRAN packages should use only the public API. Hence they should not use entry points not declared as API in installed headers nor .Internal() nor .Call() etc calls to base packages. Also, ::: should not be used to access undocumented/internal functions in base packages. Such usages can cause packages to break at any time, even in patched versions of R. (https://cran.r-project.org/web/packages/policies.html)

[Jason Vander Heiden]

This is probably due to these lines in Alakazam.R:

setOldClass("data.frame")
setOldClass("tbl_df")
setClassUnion("GenericDataFrame", c("data.frame", "tbl_df"))

Which are meant to fix the probably of wanting to put either a data.frame or tbl_df into an S4 object slot. Maybe there is a better way to handle this?

[ssnn]

Yes, it's due to these lines. The hack I found is not recommended, because of CRAN's policy on the usage of ':::'. We will need to figure out another way.

[ssnn]

Maybe just coercing: as.data.frame(my_tbl_df)

[Jason Vander Heiden]

That's what I did originally, but it would be nice to maintain things as a tbl_df if they start that way.

[ssnn]

We thought the same them. I also used coercion first but thought that it would be more efficient to avoid it and then defined the class union

[Jason Vander Heiden]

Went ahead and swapped the data.frame and tbl_df class union for coercion to data.frame in both alakazam and shm.