Inline code chunks are broken by linebreaks

[aammd]

When a .Rmd file is written in a text editor that wraps lines at a ruler, sometimes a linebreak falls in the middle of an inline code chunk. This causes an error when the document is knit. Is it possible to modify knitr to ignore linebreaks in inline code chunks?

Also see http://stackoverflow.com/q/19819972/559676

[yihui]

should be fixed now; please test the current development version: https://github.com/yihui/knitr#readme

[krlmlr]

Doesn't seem to work, see commit above in https://github.com/krlmlr/knitr-examples/tree/655-inline-linebreak

[yihui]

Interesting. It works for me.

[krlmlr]

Well, just tested with fresh code from your master:

./k 107-inline-linebreak.Rmd
Error in base::parse(text = code, srcfile = NULL) : 
  3:0: unexpected end of input
1: paste("to span",
2: #' "over several lines")
  ^
[1] "107-inline-linebreak.md"

Cleaned the cache up front, too...

[yihui]

I see. That is an R script for spin(), not really an Rmd file. An Rmd file should be this:

Inline expressions such as `r "the following"` are now allowed `r paste("to span",
"over several lines")`.

[aammd]

It works for my source code, and example 107 -- but only if the \n does NOT fall exactly after the `r at the start of the inline code.

Inline expressions such as `r "the following"` are now allowed `r
 paste("to span","over several lines")`.

doesn't work.

[yihui]

@aammd Now I remember why I disallowed line breaks in the past; that is because sometimes we may write a plain R code block

```r
1 + 1
```

which is not supposed to be evaluated. In this case, allowing line breaks for inline expressions can be troublesome, because such a code block may be identified as an inline expression when you have a space after r.

```r[space_here]
1 + 1
```

Anyway, I think it should be reasonable to support line breaks inside an inline expression, but not in the beginning of an expression.

@krlmlr I believe unit tests are more appropriate, instead of writing examples for each document format, because the examples are very short.

[krlmlr]

Unfortunately, most automatic word wrappers don't know about this specialty, and would also wrap just after r if it fits. Can this be solved using a negative lookbehind?

Also, what about Rnw files and \Sexpr{}?

[yihui]

\Sexpr{} is different. I require a space after r in markdown because it is rare for one to write r that is not supposed to be an inline code expression. For \Sexpr{}, it is not necessary to require a space, because it is simply not a valid LaTeX command at all.

Looking behind is certainly possible, but it will probably make R Markdown an exception in the parser, because I'll have to use Perl regular expressions. I do not have much brain power to think about this at the moment, for reasons that you know :)

[isomorphisms]

I'm still getting this error, apparently a couple years after the fix. rmarkdown::render("my file.Rmd", "my file.html") is my incantation.

[yihui]

@isomorphisms A minimal reproducible example please. This works for me:

aaa `r 1+
1` bbb

[github-actions]

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