AT_SETUP([identifiers])
AT_KEYWORDS([scan])
AT_DATA([input], [dnl
-a aB i5 $x @efg @@. #.# .x _z.
+a aB i5 $x @efg @@. !abcd #.# .x _z.
abcd. abcd.
QRSTUV./* end of line comment */
QrStUv./* end of line comment */ @&t@
SKIP
ID "@@."
SKIP
+MACRO_ID "!abcd"
+SKIP
ID "#.#"
SKIP
UNEXPECTED_DOT
SKIP
SKIP
ID "#"
-UNEXPECTED_CHAR 33
+MACRO_ID "!"
SKIP
SLASH
ID "usr"