Text wrapping with long lists mangles command input

[dahcase]

Prework

• [x ] Read and abide by drake's code of conduct.
• [x ] Search for duplicates among the existing issues, both open and closed.

Great package! Apologies in advance if I missed a relevant issue.

Description

Vectors of over 12+ units long (and/or a character limit of about 80+) seems to be throwing the translation of the command into the call for a bit of a loop. Specifically, something about how the command is constructed is between row 12 and 13 introduces another c and then I think this outer c has commas where line breaks are.

Reproducible example

library('drake')
lll = lapply(1:20, function(x) rep('a',x))
ppp = drake_plan(a = target(length(x), transform = map(x =  !!lll, y = !!seq_along(lll), .id = y))) #81 characters seems to be near the max

#seems like the parsing into a call/tidying up the code is causing the issue.
lens = sapply(ppp[,2], function(x) eval(x))
all.equal(lens, sapply(lll, length)) #don't line up
#> [1] "Mean relative difference: 7.25"

Session info

R version 3.6.0 (2019-04-26)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

Matrix products: default

locale:
[1] LC_COLLATE=English_United States.1252 LC_CTYPE=English_United States.1252 LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C LC_TIME=English_United States.1252

attached base packages:
[1] stats graphics grDevices utils datasets methods base

other attached packages:
[1] reprex_0.3.0 drake_7.3.0

loaded via a namespace (and not attached):
[1] Rcpp_1.0.1 ps_1.3.0 digest_0.6.19 R6_2.4.0 backports_1.1.4 storr_1.2.1 magrittr_1.5 evaluate_0.13 rlang_0.3.4
[10] fs_1.3.1 callr_3.2.0 whisker_0.3-2 rmarkdown_1.13 tools_3.6.0 igraph_1.2.4.1 processx_3.3.1 xfun_0.7 yaml_2.2.0
[19] compiler_3.6.0 pkgconfig_2.0.2 base64url_1.4 clipr_0.6.0 htmltools_0.3.6 knitr_1.23

Expected output

Admittedly, the plan does not have an output, but I would expect a vector of 1:20

[wlandau]

Glad you spotted this. It will become important for transform = split() on index sets (next CRAN release, end of this section). Fixed in f1b45c6.