Wrap long lines

[lorenzwalthert]

Reference: #390.

[lorenzwalthert]

• rebasing on master and resolve merge conflicts.
• apply styler to the PR.
• replace base R calls to apply() and friends with purrr equivalents.
• replace the repeat() and while() statements with recursions.
• documenting with roxygen.
• adding unit tests and thinking of exceptions.
• some minor code refactoring (i.e. don't define functions within functions, function re-naming, exposing of the width argument).

[lorenzwalthert]

Potential problems with the current implementation are noted in
#247 (comment)

[krlmlr]

I'm seeing:

styler::style_text("1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1")
#> 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
#> 
#>   1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1
#>   + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1

^{Created on 2018-09-18 by the reprex package (v0.2.1)}

All lines must end in a + .

[krlmlr]

Moreover, the following loops indefinitely:

styler::style_text('styler::style_text("1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1")')

[lorenzwalthert]

Ok, merging this now (not into master, just into the r-lib devel branch). Thanks @krivit.

[pat-s]

Has the line-with branch ever been tried out in practice? I would be willing to though it would need a rebase with master - and I am afraid to run into merge conflicts :)

[lorenzwalthert]

Let's continue this discussion in #496.