backports doesn't export `str2expression`?

[ngreifer]

It came to my attention that backports does not export all functions from previous R releases, including str2expression (and the related str2lang). If this was deliberate, is there a reason for it? Thanks.

[dmurdoch]

I'd guess it's just that nobody has submitted them. It should be a really easy PR, since the current R source gives R equivalents (though it actually uses C based internals). See https://github.com/wch/r-source/blob/cd1d256fb2f288af67b3d51b1ee44e97064c285f/src/library/base/R/parse.R#L60 .