1 files changed, 10 insertions, 4 deletions

diff --git a/rng.ha b/rng.ha
index 93405b4..24e5177 100644
--- a/rng.ha
+++ b/rng.ha
@@ -6,6 +6,7 @@ use os;
 use strconv;
 use sort;
 use sort::cmp;
+use io;
 
 export fn main() void = {
 	const cmd = getopt::parse(os::args,
@@ -58,16 +59,21 @@ export fn main() void = {
 		sort::sort(rngs: []opaque, size(u32), &cmp::u32s);
 	};
 
-	printrngs(rngs, sep);
+	match (printrngs(rngs, sep)) {
+	case void =>
+		yield;
+	case let e: io::error =>
+		fmt::fatal(io::strerror(e));
+	};
 };
 
-fn printrngs(rngs: []u32, sep: str) void = {
+fn printrngs(rngs: []u32, sep: str) (void | io::error) = {
 	let s = "";
 	for (const rng .. rngs) {
-		fmt::printf("{}{}", s, rng)!;
+		fmt::printf("{}{}", s, rng)?;
 		s = sep;
 	};
-	fmt::println()!;
+	fmt::println()?;
 };
 
 fn contains(a: []u32, b: u32) bool = {