An alternative to scan() in R (here-document style) - r

Question

I am looking for a way to read text into a vector such that each line would be a different element, all happening within an R script.
One way that I found was something like:
bla <- scan(text = "line1
line2
line3",
what = character())
Which correctly gives me:
> bla
[1] "line1" "line2" "line3"
However, there are several problems. First, it is indented. I don't have to, but any auto indentation features will just pop it back to be aligned (which I commonly use). Second, this requires escape codes if I would like to use the double quote symbol for example.
Is there a way to do something similar to the Here-Document method (<< EOF), in R scripts?
I am using RStudio as my IDE, running on Windows. Preferably there would be a platform independent way of doing this.
EDIT
Do you need to have the text inside the R script?
Yes.
An example of what I want to do:
R script here
⋮
bla <- <SOMETHING - BEGIN>
line1
line2
line3
<SOMETHING - END>
⋮
more R script here
Where the requirement, again, is that I can type freely without worrying about auto indentation moving the lines forward, and no need to worry about escape codes when typing things like ".

Answer 1

Both problems can be solved with the scan function and two little tricks, I think:
scan(text = '
line1
"line2" uses quotation mark
line3
', what = character(), sep = "\n")
Read 3 items
[1] "line1" "\"line2\" uses quotation mark"
[3] "line3"
When you put the quotation marks in a line of their own, you don't have a problem with auto indentation (tested using RStudio). If you only have double quotation marks in the text, you can use single quotation marks to start and end your character object. If you have single quotation marks in the text, use double quotation marks for character. If you have both, you should probably use search and replace to make them uniform.
I also added sep = "\n", so every line is one element of the resulting character vector.

Answer 2

Since R version 4.0, we have raw strings (See ?Quotes)
bla <- r"(line1
line2
"line3"
'line4'
Here is indentation
Here is a backslash \
)"
#> [1] "line1\nline2\n\"line3\"\n'line4'\n Here is indentation\nHere is a backslash \\\n"
Note though it gives one single string, not separate elements. We can split it back with strsplit:
bla <- strsplit(bla, "\n")[[1]]
#> [1] "line1"
#> [2] "line2"
#> [3] "\"line3\""
#> [4] "'line4'"
#> [5] " Here is indentation"
#> [6] "Here is a backslash \\"

Answer 3

If authoring an Rmarkdown document instead of an R script is an option, we could use the knitr cat engine
---
title: "Untitled"
output: html_document
---
```{cat engine.opts=list(file='foo')}
line1
line2
"line3"
'line4'
```
```{r}
bla <- readLines("foo")
bla
```