add compare test script

assignments/PA3/Makefile

@@ -75,3 +75,10 @@ clean-compile:
 	${SHELL} -ec '${DEPEND} $< | sed '\''s/\($*\.o\)[ :]*/\1 $@ : /g'\'' > $@'
 
 -include ${CFIL:.cc=.d}
+
+TESTCASE = good.cl
+comparetest: parser
+	./stdparser ${TESTCASE} > std.out
+	./myparser ${TESTCASE} > my.out
+	diff std.out my.out
+	rm std.out my.out

assignments/PA3/stdparser

@@ -0,0 +1,2 @@
+#!/bin/bash -f
+../../bin/lexer $* | ../../bin/parser $*