Centralize file mimetype detection in mime.kak

This way, 'file --mime-type $buffer' is called only once per file
rather than once per filetype detection hook.

src/Makefile

@@ -41,6 +41,6 @@ XDG_CONFIG_HOME ?= $(HOME)/.config
 
 userconfig:
 	mkdir -p $(XDG_CONFIG_HOME)/kak/autoload
-	ln -s $(CURDIR)/rc/{asciidoc,client,cpp,diff,git,grep,kakrc,make,sh,mail,man}.kak $(XDG_CONFIG_HOME)/kak/autoload/
+	ln -s $(CURDIR)/rc/{asciidoc,client,cpp,diff,git,grep,kakrc,mime,make,sh,mail,man}.kak $(XDG_CONFIG_HOME)/kak/autoload/
 
 .PHONY: tags userconfig

src/rc/cpp.kak

@@ -2,12 +2,9 @@ hook global BufCreate .*\.(c|cc|cpp|cxx|C|h|hh|hpp|hxx|H) %{
     set buffer filetype cpp
 }
 
-hook global BufOpen .* %{ %sh{
-     mimetype="$(file -b --mime-type ${kak_bufname})"
-     if [[ "${mimetype}" == "text/x-c++" || "${mimetype}" == "text/x-c" ]]; then
-         echo set buffer filetype cpp;
-     fi
-} }
+hook global BufSetOption mimetype=text/x-c(\+\+)? %{
+    set buffer filetype cpp
+}
 
 hook global WinSetOption filetype=cpp %~
     addhl group cpp-highlight
@@ -35,6 +32,8 @@ hook global WinSetOption filetype=cpp %~
         try %{ exec -draft <c-s>k<a-x>s^\h*\K(/{2,})<ret>y<c-o>P }
         # indent after visibility specifier
         try %[ exec -draft k<a-x><a-k>^\h*(public|private|protected):\h*$<ret>j<a-gt> ]
+        # indent after if|else|while|for
+        try %[ exec -draft <a-F>)MB<a-k>\`(if|else|while|for)\h*\(.*\)\n\h*\n\'<ret><a-space><space><a-gt> ]
     _ @
 
     hook window InsertChar \} -id cpp-indent %[

src/rc/mail.kak

@@ -1,9 +1,4 @@
-hook global BufOpen .* %{ %sh{
-     mimetype="$(file -b --mime-type ${kak_bufname})"
-     if [[ "${mimetype}" == "message/rfc822" ]]; then
-         echo set buffer filetype mail;
-     fi
-} }
+hook global BufSetOption mimetype=message/rfc822 %{ set buffer filetype mail }
 
 hook global WinSetOption filetype=mail %~
     addhl group mail-highlight

src/rc/mime.kak

@@ -0,0 +1,5 @@
+decl str mimetype "text/plain"
+
+hook global BufOpen .* %{
+     set buffer mimetype %sh{file -b --mime-type ${kak_bufname} }
+}

src/rc/sh.kak

@@ -2,12 +2,9 @@ hook global BufCreate .*\.(sh) %{
     set buffer filetype sh
 }
 
-hook global BufOpen .* %{ %sh{
-     mimetype="$(file -b --mime-type ${kak_bufname})"
-     if [[ "${mimetype}" == "text/x-shellscript" ]]; then
-         echo set buffer filetype sh;
-     fi
-} }
+hook global BufSetOption mimetype=text/x-shellscript %{
+    set buffer filetype sh
+}
 
 hook global WinSetOption filetype=sh %~
     addhl group sh-highlight