parse: show error on test failure

parse/+test/lexer.ha

@@ -13,6 +13,8 @@ use io;
 				mkword("def")]),
 		(`#t #f`, [true, false]),
 		(`#\a #\space #\nul`, ['a', ' ', '\0']),
+		(`"\x0a;" "\x2014;" "\x2f9f4;"`, ["\n", "—", "嶲"]),
+		(`#\x #\x0a; #\x2014; #\x2f9f4;`, ['x', '\n', '—', '嶲']),
 	];
 
 	for (let i = 0z; i < len(cases); i += 1) {
@@ -23,7 +25,16 @@ use io;
 
 		for (let j = 0z; j < len(cases[i].1); j += 1) {
 			const want = cases[i].1[j];
-			const have = lex(&lexer)! as token;
+			const have = match (lex(&lexer)) {
+			case let tok: token =>
+				yield tok;
+			case io::EOF =>
+				assert(false, "reached EOF");
+				return;
+			case let err: error =>
+				assert(false, strerror(err));
+				return;
+			};
 
 			if (!tokeq(want, have)) {
 				fmt::printfln("Case {}: {}", i, cases[i].0)!;

parse/types.ha

@@ -22,10 +22,10 @@ export fn strerror(err: error) const str = {
 	match (err) {
 	case let err: invalid =>
 		return fmt::bsprintf(buf,
-			"{}:{}: Invalid token found", err.0, err.1);
+			"Invalid token found at {}:{}", err.0, err.1);
 	case let err: unterminated =>
 		return fmt::bsprintf(buf,
-			"{}:{}: Unterminated {} found", err.1, err.2, err.0);
+			"Unterminated {} found at {}:{}", err.0, err.1, err.2);
 	case let err: io::error =>
 		return io::strerror(err);
 	};