Add the typstyle formatter as a fixer for Typst (#4927)

Co-authored-by: Adrian Vollmer <computerfluesterer@protonmail.com>

autoload/ale/fix/registry.vim

@@ -707,6 +707,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['clojure'],
 \       'description': 'formatter and linter for clojure files',
 \   },
+\   'typstyle': {
+\       'function': 'ale#fixers#typstyle#Fix',
+\       'suggested_filetypes': ['typst'],
+\       'description': 'A formatter for Typst files',
+\   },
 \}
 
 " Reset the function registry to the default entries.

autoload/ale/fixers/typstyle.vim

@@ -0,0 +1,20 @@
+" Author: Adrian Vollmer (computerfluesterer@protonmail.com)
+" Description: Typst formatter using typstyle
+
+call ale#Set('typst_typstyle_executable', 'typstyle')
+call ale#Set('typst_typstyle_use_global', get(g:, 'ale_use_global_executables', 0))
+call ale#Set('typst_typstyle_options', '')
+
+function! ale#fixers#typstyle#Fix(buffer) abort
+    let l:executable = ale#path#FindExecutable(
+    \   a:buffer,
+    \   'typst_typstyle',
+    \   ['typstyle']
+    \)
+
+    let l:options = ale#Var(a:buffer, 'typst_typstyle_options')
+
+    return {
+    \   'command': ale#Escape(l:executable) . ' ' . l:options,
+    \}
+endfunction