feature request: support curly braces in eg. path()

[torbjorn]

Would be nice to be able to do:

horse <- "silver"
my_path <- path("hi", "ho", "{horse}_away")

... So we don't have to do additional glue's on every element of the path. One could quickly feel tempted to just glue the whole thing then, which would be unfortunate.

[gaborcsardi]

We cannot do that, that is a breaking change. If you like, you can write a helper function, that calls glue for each element, and then creates a path from the results.

If you do that, note that {} characters are allowed in file paths, so be carefule not to call your helper function on variables from the user, as they may contain {} characters.

[torbjorn]

Yes, that makes sense

Would it be feasible to adopt a pathg (or similar) function for this into fs? Curly brace notation is already making it's way into multiple packages in tidyverse.

But it's also a design philosophy change that likely means a pletora of functions in fs now would be expected to have a g sister function for glue extrapolation, so it's probably a too big ask.

[gaborcsardi]

Yeah, I don't think that's a good way forward. That would mean that we should add a *g() variant to pretty much every function that takes string or character inputs, in all of our packages.

Ideally, R would support this natively, with new syntax. Many languages have made that change. E.g., similarly to the new r"{....}" raw strings, R could have f"..."that interpolates{expr}` expressions.