#!/bin/sh
# This is a shar archive.
# The rest of this file is a shell script which will extract:
#
# 3_12.c 3_12.cmp 3_12.in 3_12a.c 3_12b1.c 3_12tst.c makefile
#
# To extract the files from this shell archive file simply
# create a directory for this file, move the archive file
# to it and enter the command
#
#	sh filename
# 
# The files will be extracted automatically.
# Note: Do not use csh.
#
# Archive created: Mon Jul 30 22:58:02 EDT 1990
#
echo x - 3_12.c
sed 's/^X//' > 3_12.c << '!EOF!'
/* Copyright (c) 1990 by AT&T Bell Telephone Laboratories, Incorporated. */
/* The C++ Answer Book */
/* Tony Hansen */
/* All rights reserved. */
// Read a token into the buffer.
// Read a line at a time.
#include <stdlib.h>
#include <error.h>

token_value get_token()
{
    static char linebuf[512] = "";
    static int lineindex = 0;

    // if line is empty, fill it
    if (linebuf[lineindex] == '\0')
	{
	if (!cin.get(linebuf, sizeof linebuf - 1))
	    return (curr_tok = END);

	// discard newline from input
	char c;
	cin.get(c);

	// install newline within line
	int end = strlen(linebuf);
	linebuf[end++] = '\n';
	linebuf[end] = '\0';
	lineindex = 0;
	}

    // delete leading whitespace on the line
    while (isspace(linebuf[lineindex]) &&
	   (linebuf[lineindex] != '\n'))
	lineindex++;

    // match a token
    char ch;
    switch (ch = linebuf[lineindex++])
	{
	case ';': case '\n':
	    return (curr_tok = PRINT);

	case '*': case '+': case '(':
	case '/': case '-': case ')':
	case ':':
	    return (curr_tok = ch);

	// match a number
	case '0': case '1': case '2': case '3':
	case '4': case '5': case '6': case '7':
	case '8': case '9': case '.':
	    int saveindex = lineindex - 1;
	    while (isdigit(ch = linebuf[lineindex]) ||
		   (ch == '.'))
		lineindex++;

	    linebuf[lineindex] = '\0';
	    number_value = atof(&linebuf[saveindex]);
	    linebuf[lineindex] = ch;
	    return (curr_tok = NUMBER);

	default:
	    if (isalpha(ch))
		{
		char *p = name_string;
		for (*p++ = ch;
		     isalnum(ch = linebuf[lineindex]);
		     *p++ = ch, lineindex++)
		    ;
		*p = '\0';
		return (curr_tok = NAME);
		}

	    error("unknown token received");
	    return (curr_tok = PRINT);
	}
}
!EOF!
ls -l 3_12.c
echo x - 3_12.cmp
sed 's/^X//' > 3_12.cmp << '!EOF!'
curr_tok=#
numb='32'
curr_tok=+
curr_tok=#
numb='495'
curr_tok=-
curr_tok=#
numb='27'
curr_tok=P
curr_tok=N
name='foo'
curr_tok=+
curr_tok=#
numb='99'
curr_tok=P
!EOF!
ls -l 3_12.cmp
echo x - 3_12.in
sed 's/^X//' > 3_12.in << '!EOF!'
32+495-27
foo+99
!EOF!
ls -l 3_12.in
echo x - 3_12a.c
sed 's/^X//' > 3_12a.c << '!EOF!'
/* Copyright (c) 1990 by AT&T Bell Telephone Laboratories, Incorporated. */
/* The C++ Answer Book */
/* Tony Hansen */
/* All rights reserved. */
ch = linebuf[lineindex++]
!EOF!
ls -l 3_12a.c
echo x - 3_12b1.c
sed 's/^X//' > 3_12b1.c << '!EOF!'
/* Copyright (c) 1990 by AT&T Bell Telephone Laboratories, Incorporated. */
/* The C++ Answer Book */
/* Tony Hansen */
/* All rights reserved. */
lineindex - 1
!EOF!
ls -l 3_12b1.c
echo x - 3_12tst.c
sed 's/^X//' > 3_12tst.c << '!EOF!'
/* Copyright (c) 1990 by AT&T Bell Telephone Laboratories, Incorporated. */
/* The C++ Answer Book */
/* Tony Hansen */
/* All rights reserved. */
#include <stream.h>
#include <string.h>
#include <ctype.h>

enum token_value {
    END = 'E', PRINT='P', NUMBER='#', NAME='N',
    L1='*', L2='+', L3='(', L4=')', L5='/', L6='-', L7=':'
} curr_tok;

double number_value;
char name_string[512];

#include "3_12.c"

main()
{
    while (get_token() != END)
	{
	cout << "curr_tok=" << chr(curr_tok) << "\n";
	switch (curr_tok)
	    {
	    case NAME:	cout << "name='" << name_string << "'\n"; break;
	    case NUMBER:cout << "numb='" << number_value<< "'\n"; break;
	    }
	}

    return 0;
}
!EOF!
ls -l 3_12tst.c
echo x - makefile
sed 's/^X//' > makefile << '!EOF!'
CC= CC -I. -I../../CC
ERROR=  ../../error.o
all: 3_12tst

3_12tst: 3_12.c 3_12tst.c
	$(CC) 3_12tst.c -o 3_12tst $(ERROR)

test: all 3_12.cmp
	3_12tst < 3_12.in > 3_12.out
	cmp 3_12.out 3_12.cmp
	echo tests done
!EOF!
ls -l makefile
# The following exit is to ensure that extra garbage 
# after the end of the shar file will be ignored.
exit 0