Add status code to spec and use it on every exit

ocaml/bin/main.ml

@@ -2,5 +2,6 @@ let () =
     match Array.to_list Sys.argv with
     | _ :: tail ->
         let future = (Tori.Parsers.Argument.interpret Tori.Schema.seed tail) in
-        if future.output.message <> "" then print_endline future.output.message
+        if future.output.message <> "" then print_endline future.output.message;
+        exit future.meta.status
     | [] -> assert false

ocaml/lib/parsers/argument.ml

@@ -2,7 +2,6 @@ let interpret (past: Schema.schema) (input: string list): Schema.schema =
 
     let future = { past with output = { message = "" } } in
 
-    (* say is useful when the only change to future is the output message *)
     let say (message: string) =
         { future with output = { message = message } } in
 
@@ -19,5 +18,12 @@ let interpret (past: Schema.schema) (input: string list): Schema.schema =
         say (Schema.format_version future.meta.version)
     | ("help" | "-h" | "--help") :: _ -> say future.meta.help.long
     | head :: _ ->
-        say ("Unrecognized command: " ^ head ^ "\n" ^ future.meta.help.short)
+        { future with
+            output = {
+                message =
+                    ("Unrecognized command: " ^ head ^ "\n"
+                        ^ future.meta.help.short)
+            };
+            meta = { future.meta with status = 1 };
+        }
     | _ -> future

ocaml/lib/schema/schema.ml

@@ -2,7 +2,7 @@ open Qol
 
 type version = { major: int; minor: int; patch: int }
 type help = { short: string; long: string }
-type meta = { version: version; help: help }
+type meta = { version: version; help: help; status: int }
 
 type output = { message: string; }
 
@@ -22,6 +22,7 @@ let seed: schema = {
             short = "<short help>";
             long = "<long help>";
         };
+        status = 0;
     };
     output = {
         message = "";