Update

compiler/sml.vim

@@ -0,0 +1,32 @@
+if polyglot#init#is_disabled(expand('<sfile>:p'), 'sml', 'compiler/sml.vim')
+  finish
+endif
+
+" Vim compiler file
+" Compiler:	SML/NJ Compiler
+" Maintainer:	Doug Kearns <dougkearns@gmail.com>
+" Last Change:	2020 Feb 10
+
+if exists("current_compiler")
+  finish
+endif
+let current_compiler = "sml"
+
+if exists(":CompilerSet") != 2		" older Vim always used :setlocal
+  command -nargs=* CompilerSet setlocal <args>
+endif
+
+let s:cpo_save = &cpo
+set cpo&vim
+
+CompilerSet makeprg=sml
+CompilerSet errorformat=%f:%l.%c-%\\d%\\+.%\\d%\\+\ %trror:\ %m,
+		       \%f:%l.%c\ %trror:\ %m,
+		       \%trror:\ %m
+		       \%f:%l.%c-%\\d%\\+.%\\d%\\+\ %tarning:\ %m,
+		       \%f:%l.%c\ %tarning:\ %m,
+		       \%tarning:\ %m,
+		       \%-G%.%#
+
+let &cpo = s:cpo_save
+unlet s:cpo_save