Add support for Crystal

https://crystal-lang.org

rc/filetype/crystal.kak

@@ -0,0 +1,38 @@
+# Crystal
+# https://crystal-lang.org
+
+hook global BufCreate '.*\.cr' %{
+  set-option buffer filetype crystal
+}
+
+hook global WinSetOption filetype=crystal %{
+  require-module crystal
+  add-highlighter window/ ref crystal
+  hook -group crystal window InsertChar '\n' crystal-new-line-inserted
+  hook -always -once window WinSetOption filetype=.* %{
+    remove-highlighter window/crystal
+    remove-hooks window crystal
+  }
+}
+
+provide-module crystal %[
+  add-highlighter shared/crystal regions
+  add-highlighter shared/crystal/code default-region group
+  add-highlighter shared/crystal/code/keywords regex '\b(abstract|alias|annotation|as|asm|begin|break|case|class|def|do|else|elsif|end|ensure|enum|extend|false|for|fun|if|include|instance_sizeof|is_a?|lib|macro|module|next|nil|nil?|of|offsetof|out|pointerof|private|protected|require|rescue|responds_to?|return|select|self|sizeof|struct|super|then|true|type|typeof|uninitialized|union|unless|until|verbatim|when|while|with|yield)\b' 0:keyword
+  add-highlighter shared/crystal/string region '"' '(?<!\\)"' regions
+  add-highlighter shared/crystal/string/fill default-region fill string
+  add-highlighter shared/crystal/string/interpolation region -recurse '\{' '#\{' '\}' fill meta
+  add-highlighter shared/crystal/comment region '#' '$' fill comment
+  define-command -hidden crystal-new-line-inserted %{
+    # Copy previous line indent
+    try %(execute-keys -draft 'K<a-&>')
+    # Remove empty line indent
+    try %(execute-keys -draft 'k<a-x>s^\h+$<ret>d')
+  }
+  define-command -hidden crystal-fetch-keywords %{
+    set-register dquote %sh{
+      curl --location https://github.com/crystal-lang/crystal/raw/master/src/compiler/crystal/syntax/lexer.cr |
+      kak -f '%1scheck_ident_or_keyword\(:(\w+\??), \w+\)<ret>y%<a-R>a<ret><esc><a-_>a<del><esc>|sort<ret>'
+    }
+  }
+]