Solve day one using ML

day_1.sml

@@ -0,0 +1,20 @@
+val file = TextIO.openIn "day_1.txt";
+val input = TextIO.inputAll file;
+TextIO.closeIn file;
+
+val result =
+    let val lines = String.tokens (fn (char) => char = #"\n") input
+    in
+		let val numbers = map
+			(fn (line) =>
+				let val digits = List.filter Char.isDigit (String.explode line)
+				in Int.fromString (String.implode [List.hd digits, List.last digits]) end)
+			lines
+		in
+			let val numbers = map Option.valOf (List.filter Option.isSome numbers)
+			in
+				List.foldl (fn (v, acc) => v + acc) 0 numbers
+			end
+		end
+	end;
+