diff --git a/rc/filetype/fsharp.kak b/rc/filetype/fsharp.kak
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+# https://fsharp.org/
+#
+
+# Detection
+# ‾‾‾‾‾‾‾‾‾
+
+hook global BufCreate .*[.](fs|fsx|fsi) %{
+    set-option buffer filetype fsharp
+}
+
+# Initialization
+# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+
+hook global WinSetOption filetype=fsharp %{
+    require-module fsharp
+
+    # indent on newline
+    hook window InsertChar \n -group fsharp-indent fsharp-indent-on-new-line
+
+    hook -once -always window WinSetOption filetype=.* %{ remove-hooks window fsharp-.+ }
+}
+
+hook -group fsharp-highlight global WinSetOption filetype=fsharp %{
+    add-highlighter window/fsharp ref fsharp
+    hook -once -always window WinSetOption filetype=.* %{ remove-highlighter window/fsharp }
+}
+
+provide-module fsharp %§
+
+# Highlighters & Completion
+# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+
+add-highlighter shared/fsharp regions
+add-highlighter shared/fsharp/code default-region group
+add-highlighter shared/fsharp/docstring region \(\*(?!\)) (\*\)) regions
+add-highlighter shared/fsharp/double_string region @?" (?<!\\)(\\\\)*"B? fill string
+add-highlighter shared/fsharp/comment region '//' '$' fill comment
+# https://docs.microsoft.com/en-us/dotnet/fsharp/language-reference/attributes 
+add-highlighter shared/fsharp/attributes region "\[<" ">\]" fill meta
+
+add-highlighter shared/fsharp/docstring/ default-region fill comment
+# ability to write highlighted code inside docstring:
+add-highlighter shared/fsharp/docstring/ region '>>> \K' '\z' ref fsharp
+add-highlighter shared/fsharp/docstring/ region '\.\.\. \K' '\z' ref fsharp
+
+evaluate-commands %sh{
+    # Grammar
+    meta="open"
+
+    # exceptions taken from fsharp.vim colors (https://github.com/fsharp/vim-fsharp)
+    exceptions="try|failwith|failwithf|finally|invalid_arg|raise|rethrow"
+
+    # keywords taken from fsharp.vim colors (https://github.com/fsharp/vim-fsharp)
+    keywords="abstract|as|assert|base|begin|class|default|delegate"
+    keywords="${keywords}|do|done|downcast|downto|elif|else|end|exception"
+    keywords="${keywords}|extern|for|fun|function|global|if|in|inherit|inline"
+    keywords="${keywords}|interface|lazy|let|match|member|module|mutable"
+    keywords="${keywords}|namespace|new|of|override|rec|static|struct|then"
+    keywords="${keywords}|to|type|upcast|use|val|void|when|while|with"
+    keywords="${keywords}|async|atomic|break|checked|component|const|constraint"
+    keywords="${keywords}|constructor|continue|decimal|eager|event|external"
+    keywords="${keywords}|fixed|functor|include|method|mixin|object|parallel"
+    keywords="${keywords}|process|pure|return|seq|tailcall|trait|yield"
+    # additional operator keywords (Microsoft.FSharp.Core.Operators)
+    keywords="${keywords}|box|hash|sizeof|nameof|typeof|typedefof|unbox|ref|fst|snd"
+    keywords="${keywords}|stdin|stdout|stderr"
+    # math operators (Microsoft.FSharp.Core.Operators)
+    keywords="${keywords}|abs|acos|asin|atan|atan2|ceil|cos|cosh|exp|floor|log"
+    keywords="${keywords}|log10|pown|round|sign|sin|sinh|sqrt|tan|tanh"
+
+
+    types="array|bool|byte|char|decimal|double|enum|exn|float"
+    types="${types}|float32|int|int16|int32|int64|lazy_t|list|nativeint"
+    types="${types}|obj|option|sbyte|single|string|uint|uint32|uint64"
+    types="${types}|uint16|unativeint|unit"
+
+    fsharpCoreMethod="printf|printfn|sprintf|eprintf|eprintfn|fprintf|fprintfn"
+
+    # Add the language's grammar to the static completion list
+    printf '%s\n' "hook global WinSetOption filetype=fsharp %{
+        set-option window static_words ${values} ${meta} ${exceptions} ${keywords} ${types}
+    }" | tr '|' ' '
+
+    # Highlight keywords
+    printf '%s\n' "
+        add-highlighter shared/fsharp/code/ regex '\b(${meta})\b' 0:meta
+        add-highlighter shared/fsharp/code/ regex '\b(${exceptions})\b' 0:function
+        add-highlighter shared/fsharp/code/ regex '\b(${fsharpCoreMethod})\b' 0:function
+        add-highlighter shared/fsharp/code/ regex '\b(${keywords})\b' 0:keyword
+    "
+}
+
+# computation expression keywords prefixed with !
+add-highlighter shared/fsharp/code/ regex "\w+!" 0:keyword
+# brackets
+add-highlighter shared/fsharp/code/ regex "[\[\]\(\){}]" 0:bracket
+# accomodate typically overloaded operators
+add-highlighter shared/fsharp/code/ regex "\B(<<>>|<\|\|>)\B" 0:operator
+# fsharp operators
+add-highlighter shared/fsharp/code/ regex "\B(->|<-|<=|>=)\B" 0:operator
+add-highlighter shared/fsharp/code/ regex "(\b(not)\b|\b(and)\b)" 0:operator
+add-highlighter shared/fsharp/code/ regex (?<=[\w\s\d'"_])((\?)([><+-/*%=]{1,2})(\??)|(\??)([><+-/*%=]{1,2})(\?)) 0:operator
+add-highlighter shared/fsharp/code/ regex (?<=[\w\s\d'"_])((\|)+>|<(\|)+|<@|@>|<@@|@@>|:>|:\?|:=|(!|#)(?=\w)|:\?>|\?|~([-+]|(~){0,2})) 0:operator
+add-highlighter shared/fsharp/code/ regex (?<=[\w\s\d'"_])(<>|::|\h\|\h|(\|\|)+|@|\.\.|<=|>=|(<)+|(>)+|!=|==|\|\|\||(\^)+|(&)+|\+|-|(\*)+|//|/|%+|=) 0:operator
+add-highlighter shared/fsharp/code/ regex (?<=[\w\s\d'"_])((?<![=<>!])=(?![=])|[+*-]=) 0:builtin
+# integer literals
+add-highlighter shared/fsharp/code/ regex %{(?<!\.)\b[1-9]('?\d+)*(u?(l|L|y|s|n)?|[IMm])\b(?!\.)} 0:value
+add-highlighter shared/fsharp/code/ regex %{(?<!\.)\b0b[01]('?[01]+)*(u?(l|L|y|s|n)?|[IMm])\b(?!\.)} 0:value
+add-highlighter shared/fsharp/code/ regex %{(?<!\.)\b0('?[0-7]+)*(u?(l|L|y|s|n)?|[IMm])\b(?!\.)} 0:value
+add-highlighter shared/fsharp/code/ regex %{(?<!\.)\b0x[\da-fA-F]('?[\da-fA-F]+)*(u?(l|L|y|s|n)?)?\b(?!\.)} 0:value
+# floating point literals
+add-highlighter shared/fsharp/code/ regex %{(?i)(?<!\.)\b\d('?\d+)*\.((lf|[fm])\b|\B)(?!\.)} 0:value
+add-highlighter shared/fsharp/code/ regex %{(?i)(?<!\.)\b\d('?\d+)*\.?e[+-]?\d('?\d+)*(lf|[fm])?\b(?!\.)} 0:value
+add-highlighter shared/fsharp/code/ regex %{(?i)(?<!\.)(\b(\d('?\d+)*)|\B)\.\d('?[\d]+)*(e[+-]?\d('?\d+)*)?(lf|[fm])?\b(?!\.)} 0:value
+add-highlighter shared/fsharp/code/ regex %{(?i)(?<!\.)\b0x[\da-f]('?[\da-f]+)*((lf|[fm])\b|\B)(?!\.)} 0:value
+add-highlighter shared/fsharp/code/ regex %{(?i)(?<!\.)\b0x[\da-f]('?[\da-f]+)*\.?p[+-]?\d('?\d+)*)?(lf|[fm])?\b(?!\.)} 0:value
+add-highlighter shared/fsharp/code/ regex %{(?i)(?<!\.)\b0x([\da-f]('?[\da-f]+)*)?\.\d('?[\d]+)*(p[+-]?\d('?\d+)*)?(lf|[fm])?\b(?!\.)} 0:value
+# character literals
+add-highlighter shared/fsharp/code/char regex %{\B'((\\.)|[^'\\])'(\b(B)|\B)} 0:value
+# other literals
+add-highlighter shared/fsharp/code/ regex "\b(true|false)\b" 0:value
+add-highlighter shared/fsharp/code/ regex "\B(\(\))\B" 0:value
+
+# Commands
+# ‾‾‾‾‾‾‾‾
+
+define-command -hidden fsharp-indent-on-new-line %{
+    evaluate-commands -draft -itersel %{
+        # copy '//' comment prefix and following white spaces
+        try %{ execute-keys -draft k <a-x> s ^\h*//\h* <ret> y jgh P }
+        # preserve previous line indent
+        try %{ execute-keys -draft \; K <a-&> }
+        # cleanup trailing whitespaces from previous line
+        try %{ execute-keys -draft k <a-x> s \h+$ <ret> d }
+        # indent after line ending with =
+        try %{ execute-keys -draft <space> k <a-x> <a-k> =$ <ret> j <a-gt> }
+        # indent after line ending with "do"
+        try %{ execute-keys -draft <space> k <a-x> <a-k> do$ <ret> j <a-gt> }
+    }
+}
+
+§