Problem with multi-line calls

[hadley]

cat(downlit::highlight("mean('\n\n')"))
#> <span class='nf'><a href='https://rdrr.io/r/base/mean.html'>mean</a></span>(<span class='s'>'
#> 
#> '</span>ean('
#> 
#> ')

^{Created on 2020-07-31 by the reprex package (v0.3.0)}

[hadley]

The key problem is that highlight() expects tokens to occupy only a single line (i.e. line1 == line2). This will probably need a fundamentally different approach to solve.