1 files changed, 103 insertions, 0 deletions
diff --git a/rc/filetype/lua.kak b/rc/filetype/lua.kak
new file mode 100644
index 00000000..605148e0
--- /dev/null
+++ b/rc/filetype/lua.kak
@@ -0,0 +1,103 @@
+# http://lua.org
+# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+
+# Detection
+# ‾‾‾‾‾‾‾‾‾
+
+hook global BufCreate .*[.](lua) %{
+    set-option buffer filetype lua
+}
+
+# Highlighters
+# ‾‾‾‾‾‾‾‾‾‾‾‾
+
+add-highlighter shared/lua regions
+add-highlighter shared/lua/code default-region group
+add-highlighter shared/lua/raw_string  region -match-capture '\[(=*)\['   '\](=*)\]'       fill string
+add-highlighter shared/lua/raw_comment region -match-capture '--\[(=*)\[' '\](=*)\]'       fill comment
+add-highlighter shared/lua/double_string region '"'   (?<!\\)(?:\\\\)*" fill string
+add-highlighter shared/lua/single_string region "'"   (?<!\\)(?:\\\\)*' fill string
+add-highlighter shared/lua/comment       region '--'  $                 fill comment
+
+add-highlighter shared/lua/code/ regex \b(and|break|do|else|elseif|end|false|for|function|goto|if|in|local|nil|not|or|repeat|return|then|true|until|while)\b 0:keyword
+
+# Commands
+# ‾‾‾‾‾‾‾‾
+
+define-command lua-alternative-file -docstring 'Jump to the alternate file (implementation ↔ test)' %{ evaluate-commands %sh{
+    case $kak_buffile in
+        *spec/*_spec.lua)
+            altfile=$(eval printf %s\\n $(printf %s\\n $kak_buffile | sed s+spec/+'*'/+';'s/_spec//))
+            [ ! -f $altfile ] && echo "echo -markup '{Error}implementation file not found'" && exit
+        ;;
+        *.lua)
+            path=$kak_buffile
+            dirs=$(while [ $path ]; do printf %s\\n $path; path=${path%/*}; done | tail -n +2)
+            for dir in $dirs; do
+                altdir=$dir/spec
+                if [ -d $altdir ]; then
+                    altfile=$altdir/$(realpath $kak_buffile --relative-to $dir | sed s+[^/]'*'/++';'s/.lua$/_spec.lua/)
+                    break
+                fi
+            done
+            [ ! -d $altdir ] && echo "echo -markup '{Error}spec/ not found'" && exit
+        ;;
+        *)
+            echo "echo -markup '{Error}alternative file not found'" && exit
+        ;;
+    esac
+    printf %s\\n "edit $altfile"
+}}
+
+define-command -hidden lua-indent-on-char %{
+    evaluate-commands -no-hooks -draft -itersel %{
+        # align middle and end structures to start and indent when necessary, elseif is already covered by else
+        try %{ execute-keys -draft <a-x><a-k>^\h*(else)$<ret><a-\;><a-?>^\h*(if)<ret>s\A|\z<ret>)<a-&> }
+        try %{ execute-keys -draft <a-x><a-k>^\h*(end)$<ret><a-\;><a-?>^\h*(for|function|if|while)<ret>s\A|\z<ret>)<a-&> }
+    }
+}
+
+define-command -hidden lua-indent-on-new-line %{
+    evaluate-commands -no-hooks -draft -itersel %{
+        # preserve previous line indent
+        try %{ execute-keys -draft <space>K<a-&> }
+        # remove trailing white spaces from previous line
+        try %{ execute-keys -draft k<a-x>s\h+$<ret>d }
+        # indent after start structure
+        try %{ execute-keys -draft k<a-x><a-k>^\h*(else|elseif|for|function|if|while)\b<ret>j<a-gt> }
+    }
+}
+
+define-command -hidden lua-insert-on-new-line %[
+    evaluate-commands -no-hooks -draft -itersel %[
+        # copy -- comment prefix and following white spaces
+        try %{ execute-keys -draft k<a-x>s^\h*\K--\h*<ret>yghjP }
+        # wisely add end structure
+        evaluate-commands -save-regs x %[
+            try %{ execute-keys -draft k<a-x>s^\h+<ret>"xy } catch %{ reg x '' } # Save previous line indent in register x
+            try %[ execute-keys -draft k<a-x> <a-k>^<c-r>x(for|function|if|while)<ret> J}iJ<a-x> <a-K>^<c-r>x(else|end|elseif)$<ret> # Validate previous line and that it is not closed yet
+                   execute-keys -draft o<c-r>xend<esc> ] # auto insert end
+        ]
+    ]
+]
+
+# Initialization
+# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+
+hook -group lua-highlight global WinSetOption filetype=lua %{
+    add-highlighter window/lua ref lua
+    hook -once -always window WinSetOption filetype=.* %{ remove-highlighter window/lua }
+}
+
+hook global WinSetOption filetype=lua %{
+    hook window InsertChar .* -group lua-indent lua-indent-on-char
+    hook window InsertChar \n -group lua-indent lua-indent-on-new-line
+    hook window InsertChar \n -group lua-insert lua-insert-on-new-line
+
+    alias window alt lua-alternative-file
+
+    hook -once -always window WinSetOption filetype=.* %{
+        remove-hooks window lua-.+
+        unalias window alt lua-alternative-file
+    }
+}