1 files changed, 14 insertions, 1 deletions
diff --git a/token.c b/token.c
index 2397756..6d4484d 100644
--- a/token.c
+++ b/token.c
@@ -136,7 +136,7 @@ tokenprint(const struct token *t)
 	fputs(str, stdout);
 }
 
-void
+static void
 tokendesc(char *buf, size_t len, enum tokenkind kind, const char *lit)
 {
 	const char *class;
@@ -162,6 +162,19 @@ tokendesc(char *buf, size_t len, enum tokenkind kind, const char *lit)
 		snprintf(buf, len, "<unknown>");
 }
 
+char *
+tokencheck(const struct token *t, enum tokenkind kind, const char *msg)
+{
+	char want[64], got[64];
+
+	if (t->kind != kind) {
+		tokendesc(want, sizeof(want), kind, NULL);
+		tokendesc(got, sizeof(got), t->kind, t->lit);
+		error(&t->loc, "expected %s %s, saw %s", want, msg, got);
+	}
+	return t->lit;
+}
+
 _Noreturn void error(const struct location *loc, const char *fmt, ...)
 {
 	va_list ap;