tests/testit/test-hilight.md

In highr: Syntax Highlighting for R Source Code

hi_latex() works without prompts

hi_latex('1+1')
hi_latex('  1 +    1')
hi_latex(c('  if (TRUE ){', 'foo && bar}'))

\hlnum{1}\hlopt{+}\hlnum{1}
  \hlnum{1} \hlopt{+}    \hlnum{1}
  \hlkwa{if} \hldef{(}\hlnum{TRUE} \hldef{)\{}
\hldef{foo} \hlopt{&&} \hldef{bar\}}

hi_latex() works with prompts

hi_latex('1+1', prompt = TRUE)
hi_latex(c('  if (TRUE ){', 'foo && bar}'), prompt = TRUE)

\hldef{> }\hlnum{1}\hlopt{+}\hlnum{1}
\hldef{> }  \hlkwa{if} \hldef{(}\hlnum{TRUE} \hldef{)\{}
\hldef{+ }\hldef{foo} \hlopt{&&} \hldef{bar\}}

hi_latex() preserves blank lines

hi_latex(c('1+1', '', 'foo(x=3) # comm'))

\hlnum{1}\hlopt{+}\hlnum{1}

\hlkwd{foo}\hldef{(}\hlkwc{x}\hldef{=}\hlnum{3}\hldef{)} \hlcom{# comm}

the fallback method recognizes comments, functions and strings

hi_latex('1+1 # a comment', fallback = TRUE)
hi_latex('paste("STRING", \'string\')', fallback = TRUE)

1+1 \hlcom{# a comment}
\hlkwd{paste}(\hlsng{"STRING"}, \hlsng{'string'})

the fallback mode is used when the code does not parse

has_warning(res <- hi_latex('1+1+ # comment'))
res

[1] TRUE
1+1+ \hlcom{# comment}

hilight() works even if code only contains comments

hi_latex('# only comments')

\hlcom{# only comments}

the right arrow -> is preserved

hi_latex('1 ->x # foo')

\hlnum{1} \hlkwb{->}\hldef{x} \hlcom{# foo}

blank lines before/after code are preserved

hi_latex(c('', '', '1'))
hi_latex(c('', '', '1', ''))

\hlnum{1}


\hlnum{1}

custom markup also works

hi_html('1+ 1')
my_cmd = cmd_html
my_cmd['NUM_CONST', 1] = '<span class="my num">'
hi_html('1+ 1', markup = my_cmd)
rm(my_cmd)

<span class="hl num">1</span><span class="hl opt">+</span> <span class="hl num">1</span>
<span class="my num">1</span><span class="hl opt">+</span> <span class="my num">1</span>

highr documentation built on March 6, 2026, 9:09 a.m.