BREAKING CHANGE: This deprecates the IS-(MAC|WINDOWS|LINUX|BSD) family
of global constants in favor of a native `featurep` check:
IS-MAC -> (featurep :system 'macos)
IS-WINDOWS -> (featurep :system 'windows)
IS-LINUX -> (featurep :system 'linux)
IS-BSD -> (featurep :system 'bsd)
The constants will stick around until the v3 release so folks can still
use it -- and there are still some modules that use it, but I'll phase
those uses out gradually.
Fix: #7479
Include ligature.el in a new set-font-ligatures! function, so that
"normal" (read: "font-based") ligatures can
also be controlled on a per-major mode basis from a user function
in configuration.
This commit also drops support for Emacs 27 to reduce the maintenance
burden.
BREAKING CHANGE: font ligatures for Harfbuzz/Coretext composition
table-based ligations are no longer controlled with
`+ligatures-composition-alist`, but is handled with
`+ligatures-prog-mode-list` and `+ligatures-all-modes-list` for most
common cases. See the README for the mode-specific methods
BREAKING CHANGE: the `:ui ligatures` module will not work anymore
with Emacs 27 or older. Also, there is no need to keep patched fonts
(for Fira, Hasklig, Iosevka) if you use the module. Update Emacs if
you want to keep using ligatures, or disable the module (`doom doctor`
will tell you if your current version of Emacs stopped working with
the module)
