From 64b934f390a6a1db026e5d82e5c31b0412ce0853 Mon Sep 17 00:00:00 2001
From: Peter McGoron <code@mcgoron.com>
Date: Fri, 13 Aug 2021 15:45:59 -0400
Subject: [PATCH] use Arg.bad instead of Failure exception when positional
 atomic number arguments

---
 elements.ml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/elements.ml b/elements.ml
index 846b0f0..b5a778b 100644
--- a/elements.ml
+++ b/elements.ml
@@ -32,7 +32,10 @@ module Opts = struct
 	let add_def s = match !ltype with
 	| NAME -> add_name s
 	| SYMB -> add_symb s
-	| NUMB -> add_numb (int_of_string s)
+	| NUMB -> add_numb (match int_of_string_opt s with
+		| None -> raise (Bad (Printf.sprintf "expected integer, got '%s'" s))
+		| Some x -> x
+	)
 
 	let msg = "Periodic table search\n\
 		elements -gendb file [-dbfile outfile]\n\