feat: support grain format (#474)

* feat: support grain format

* fix: formatting -> formatter

* refactor(grain): format with stdin/stdout

---------

Co-authored-by: Steven Arcangeli <506791+stevearc@users.noreply.github.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/lua/conform/formatters/grain_format.lua b/lua/conform/formatters/grain_format.lua
new file mode 100644
index 0000000..c7a1b36
--- /dev/null
+++ b/lua/conform/formatters/grain_format.lua
@@ -0,0 +1,10 @@
+---@type conform.FileFormatterConfig
+return {
+  meta = {
+    url = "https://grain-lang.org/docs/tooling/grain_cli#grain-format",
+    description = "Code formatter for the grain programming language.",
+  },
+  command = "grain",
+  args = { "format", "$FILENAME" },
+  stdin = true,
+}