R6 instantiation

[maelle]

I wanted to see how I could get

downlit::highlight("library(crul); HttpClient$new()")
#> [1] "<span class='kr'><a href='https://rdrr.io/r/base/library.html'>library</a></span><span class='o'>(</span><span class='nv'><a href='https://docs.ropensci.org/crul'>crul</a></span><span class='o'>)</span>; <span class='nv'><a href='https://docs.ropensci.org/crul/reference/HttpClient.html'>HttpClient</a></span><span class='o'>$</span><span class='nf'>new</span><span class='o'>(</span><span class='o'>)</span>"

^{Created on 2020-09-21 by the reprex package (v0.3.0.9001)}

But

• it might be adding too much complexity just for the special case of R6 instantiation;
• I can't test it without adding a dependency (or some sort of mocking);
• The usefulness of this is quite limited since downlit doesn't know what packages are really attached (compared to what knitr would know) so I'd probably be better off just namespacing (the reprex below works without any tweak). 😅

downlit::highlight("crul::HttpClient$new()")
#> [1] "<span class='nf'>crul</span><span class='nf'>::</span><span class='nv'><a href='https://docs.ropensci.org/crul/reference/HttpClient.html'>HttpClient</a></span><span class='o'>$</span><span class='nf'>new</span><span class='o'>(</span><span class='o'>)</span>"

^{Created on 2020-09-21 by the reprex package (v0.3.0.9001)}

[hadley]

downlit should know what packages are attached (subject to some minor heuristics); it keeps a record of all uses of library() and require().

[maelle]

right but it does that only for the chunk/code at hand, right? whereas knitr would know for all chunks until the one at hand? or am I missing something?

[maelle]

oooh no I see, sorry, I did miss something.

[maelle]

So that leaves two arguments against this feature:

• it might be adding too much complexity just for the special case of R6 instantiation;
• I can't test it without adding a dependency (or some sort of mocking).