downlit 0.4.0

Syntax highlighting

• Messages, warnings, and errors now get a much more minimal style.
  Messages are styled the same way as output; and warnings and errors
  only style the "Warning" or "Error" text. This makes these types of
  output easier to read, and easier for package developers to style
  themselves.

• Messages, warnings, and errors now retrieve their text using
  conditionMessage(), which supports more advanced types of conditions
  (@davidchall, #100).

• The overall structure of the syntax highlighting has been overhauled.
  Now each line is wrapped in a <span> with class r-in (input code),
  r-out (output printed to console), r-plot (plots), r-msg (messages),
  r-wrn (warnings), and r-err (errors). Additionally, the prompt (#>)
  is wrapped in a <span class="r-pr">. Altogether, these changes
  should give much more flexibility for styling with CSS (#90).

• ANSI escapes no longer generate invalid HTML (#79).

• Changes to better support for HTML widgets and rgl in pkgdown
  (@dmurdoch, #78). In particular, evaluate_and_highlight() now returns
  an additional attribute containing all extra dependencies needed to render
  the returned HTML.

Auto-linking

• Packages attached when you call library(package) (including by the
  tidyverse), are now taken into account when autolinking (#87).

• In code blocks, custom infix operators are now autolinked (#89).
  In inline code, infix operators are no longer autolinked; this lead to too
  many false positives. You can still link with (e.g.) ?"-" (#86).

• Inline calls with arguments (e.g. foo(1, 2)) are no longer auto-linked,
  as intended and documented (#82).

• Autolinking vignette(foo, package = "pkg") no longer errors if pkg is not
  installed (#85).

• Unusual help calls (e.g. help(a$b)), no longer generate errors (#77).

• Rare warning about incomplete final line in autolink_url("pkgname::foo")
  is now suppressed (@dmurdoch, pkgdown#1419).

• href_package() is now exported (#103).

• Auto-linking is more likely to succeed when the remote package is not
  installed as downlit now looks for the URL using tools::CRAN_package_db()
  for CRAN packages, and and available.packages() for packages installed
  from non-CRAN repos (@ARawles, #108).

• Functions in HTML <summary> elements are no longer autolinked
  (@gadenbuie, #105).