Fill in implementation of `crystal-insert-on-new-line`

1 files changed, 21 insertions, 4 deletions

diff --git a/rc/filetype/crystal.kak b/rc/filetype/crystal.kak
index 65378666..1a55ffde 100644
--- a/rc/filetype/crystal.kak
+++ b/rc/filetype/crystal.kak
@@ -210,12 +210,29 @@ define-command -hidden crystal-indent-on-new-line %{
     }
 }
 
-define-command -hidden crystal-insert-on-new-line %{
-    evaluate-commands -no-hooks -draft -itersel %{
+define-command -hidden crystal-insert-on-new-line %[
+    evaluate-commands -no-hooks -draft -itersel %[
         # Copy comment prefix and following whitespaces
         try %{ execute-keys -draft k <a-x> s '^\h*\K#\h*' <ret> y j gl p }
-    }
-}
+
+        # Add `end` token if needs be
+        # The 'x' register is to save the leading whitespaces of the opening token
+        evaluate-commands -save-regs x %[
+            # Save the leading whitespaces in register 'x'
+            try %{ execute-keys -draft k <a-x> s ^\h* <ret> \" x y }
+            try %[
+                evaluate-commands -draft %[
+                    # Make sure previous line opens a block
+                    execute-keys -draft k <a-x> <a-k> ^<c-r>x(?:begin|case|class|def|for|if|module|unless|until|while|.+\bdo\h\|.+(?=\|))[^0-9A-Za-z_!?] <ret>
+                    # Make sure `end` doesn't already exist on indent level
+                    execute-keys -draft }i J <a-x> <a-K> ^<c-r>x(?:end|else|elsif|rescue|when)[^0-9A-Za-z_!?] <ret>
+                ]
+                # Insert new line with end prepended by contents of register 'x'
+                execute-keys -draft o <c-r>x end <esc>
+            ]
+        ]
+    ]
+]
 
 define-command -hidden crystal-fetch-keywords %{
     set-register dquote %sh{