CS345 - Program 01 sample code

1. There are two Makefiles. One for using Flex/Bison and one for Lex/Yacc. They are 
similar, but there are differences between the two tool sets. Choose the makefile 
you want to use and rename it to Makefile or use the -f flag to the 'make' program 
as follows:

% make -f Makefile.bison

2. The file icalc.l contains a lexical specification for a very simple 
integer calculator that operates like the Linux 'bc' calculator.

3. The file icalc.y contains a context free grammar specification in 
YACC/Bison BNF for the calclulator.

4. I've tested this code using Linux on CS lab machines, and using 
Mac OS X 10.4 or later.

5. This code should work on Windows if you have the Cygwin toolset installed. 
See http://www.cygwin.com/ and be sure to download the developer tools 
including flex/bison and/or lex/yacc. To terminate the input loop on Windows, 
use <ctrl-z> instead of <ctrl-d>.

6. If everything makes correctly, you should be left with an executable file 
called 'icalc'.  A successful build and executable should look like this:



redeyedfly:~/$ make -f Makefile.bison
bison -dv -bicalc icalc.y
gcc -g -O   -c -o icalc.o icalc.c
flex -t icalc.l > scan.c
gcc -g -O   -c -o scan.o scan.c
gcc -g -O icalc.o scan.o -o icalc

redeyedfly:~/$ icalc
Welcome to iCalc 1.0. Copyright 2007. Use <ctrl-d> to quit.
iCalc# 1+2*3
7
icalc> exiting...