Leanificate R6 Classes

[mb706]

Re: #482

roundtripdiff = function(x) {
  path <- tempfile()
  saveRDS(x, file = path)
  y <- readRDS(path)
  file.remove(path)
  as.numeric(lobstr::obj_size(y)) / as.numeric(lobstr::obj_size(x))
}

task <- tsk("mtcars")
learner <- lrn("regr.rpart")
rr <- resample(task, learner, rsmp("bootstrap", repeats = 1000))
roundtripdiff(rr$data$learner)

This PR:

4.156

Whatever mlr3 version I happen to have installed:

36.991

Size of the whole rr object is 15.8 MB before serialization, 62.4 MB with this PR after serialization, and 618.3 MB with vanilla mlr3.

[codecov-commenter]

Codecov Report

Merging #509 into master will decrease coverage by 0.71%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #509      +/-   ##
==========================================
- Coverage   92.77%   92.05%   -0.72%     
==========================================
  Files          75       76       +1     
  Lines        1937     1952      +15     
==========================================
  Hits         1797     1797              
- Misses        140      155      +15     

Impacted Files	Coverage Δ
R/zzz.R	0.00% <0.00%> (ø)

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[mllg]

Thanks, look promising. We should discuss the next steps in a call.

[mb706]

Moving this to mlr3misc