Thanks for the comments and sorry I didn't reply sooner! On Thu, 30 Mar 2023 12:38:24 -0400 Duncan Murdoch <murdoch.dun...@gmail.com> wrote:
> You'd need to recurse through all expressions in the object. Some of > those expressions might be environments, so your changes could leak > out of the function you're working on. In my efforts to get arbitrary objects to hash consistently, I already walk them recursively, but I do stop at environments. (In theory, it could be possible to create mock environments with the same relationships between each other and then "fix up" and hash their contents, but it's hard to do right. Imagine environments e1 and e2 where e1$other <- e2 and e2$other <- e1.) I think that removeSource() already walks language objects recursively, it just doesn't remove source references from unevaluated function expressions. > Things are simpler if you know the expression is the unmodified > result of parsing source code, but if you know that, wouldn't you > usually be able to control things by setting keep.source = FALSE? I receive the expression object from substitute(). The idea is to hash the expression, locate and hash its dependencies and then see if there's already a file named like the resulting hash. In theory, the user could be constructing elaborate scary-looking expressions and then calling my function on them, but I think I can be reasonably certain I get the calls straight from the parser. Unfortunately, this doesn't put me in a position to be controlling options(keep.source=...). > Maybe a workable solution is something like parse(deparse(expr, > control = "exact"), keep.source = FALSE). Thanks for this idea! At some point I was considering hashing text representations of objects, but then I got serialize()-hashing working and forgot about it. -- Best regards, Ivan ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
