add test for start & atok tokens

brag/examples/start-and-atok.rkt

@@ -0,0 +1,3 @@
+#lang brag
+
+top : ("start" | "atok")+

brag/test/test-all.rkt

@@ -15,6 +15,7 @@
          "test-quotation-marks-and-backslashes.rkt"
          "test-simple-arithmetic-grammar.rkt"
          "test-simple-line-drawing.rkt"
+         "test-start-and-atok.rkt"
          "test-weird-grammar.rkt"
          "test-whitespace.rkt"
          "test-wordy.rkt"

brag/test/test-start-and-atok.rkt

@@ -0,0 +1,14 @@
+#lang racket/base
+
+(require brag/examples/start-and-atok
+         brag/support
+         rackunit)
+
+;; make sure that "start" and "atok" work as terminals.
+
+(check-equal? (parse-to-datum (list "start")) '(top "start"))
+(check-equal? (parse-to-datum (list "atok")) '(top "atok"))
+(check-equal? (parse-to-datum (list "start" "atok")) '(top "start" "atok"))
+
+
+