Robert. It is not my intention to sound rude, but several
people have already told you in past replies that
"Std_lib_facilities.h" is not part of standard C++. If you
do not intend to read and understand the replies people are
providing then you have more serious problems than code
that will not compile.
--- Robert Ryan <[EMAIL PROTECTED]> wrote:
> you will have to explain that to me. what do you use if
> not "Std_lib_facilities.h" do you use
> <iostream.h>.......since I am new to this .......this is
> what was given with the code........
> thanks
>
> "Victor A. Wagner Jr." <[EMAIL PROTECTED]> wrote:
> At 17:17 2007-02-19, Robert Ryan wrote:
> I got it solved after a lot of confusion.
>
> #include "std_lib_facilities.h"
> you realize that this is a non-standard include file.....
> the rest of us don't have it
>
>
> class Token {
> public:
> char kind; // what kind of token
> double value; // for numbers: a value
> Token(char ch) :kind(ch), value(0) { }
> Token(char ch, double val) :kind(ch), value(val) { }
> };
>
> class Token_stream {
> bool full; // is there a Token in the buffer
> Token buffer; // here is where we keep a Token put back
> using unget()
> public:
> Token get(); // get a Token (get() is defined
> elsewhere)
> void unget(Token t); // put a Token back
> Token_stream(); // make a Token_stream that reads from
> cin
> };
>
> void Token_stream::unget(Token t) // unget takes one
> argument
> {
> buffer = t; // copy t to buffer
> full = true; // buffer is now full
> }
> Token_stream::Token_stream()
> :full(false), buffer(0) // no Token in buffer
> {
> }
> Token Token_stream::get()
> {
> if (full) { // check if we already have a Token ready
> full=false;
> return buffer;
> }
> char ch;
> cin >> ch; // note that >> skips whitespace (space,
> newline, tab, etc.)
> switch (ch) {
> case '=': // print
> case 'x': // quit/exit
> case '%':
> case '(': case ')': case '+': case '-': case '*': case
> '/':
> return Token(ch); // let each character represent
> itself
> case '.':
> case '0': case '1': case '2': case '3': case '4': case
> '5': case '6': case '7': case '8': case '9':
> { cin.unget(); // put digit back into the input stream
> double val;
> cin >> val; // read a floating-point number
> return Token('8',val); // let 8 represent a number
> }
> default:
> error("Bad token");
> // XXX
> } // add (
> }
>
> Token_stream ts; // provides get() and unget()
> double expression(); // declaration so that primary()
> can call expression()
> double primary()
> {
> Token t = ts.get();
> switch (t.kind) {
> case '(': // handle ( expression )
> { double d = expression();
> t = ts.get();
> if (t.kind != ')') error("'(' expected");
> return d;
> }
> case '8': // we use '8' to represent a number
> return t.value; // return the numbers value
> default:
> error("primary expected");
> }
> }
> double term()
> {
> double left = primary();
> Token t = ts.get();
> switch (t.kind) {
> case '*':
> return left *term();
> case '/':
> { double d = term();
> if (d == 0) error("divide by zero");
> return left / d;
> }
> case '%':
> { int i1 = int(left);
> int i2 = int(term());
> return i1%i2;
> }
> default:
> ts.unget(t);
> return left;
> }
> }
> double expression()
> {
> double left = term(); // read and evaluate a Term
> Token t = ts.get(); // get the next token
> switch (t.kind) { // see which kind of token that is
> case '+':
> return left + expression(); // read and evaluate an
> Expression,
> // then do an add
> case '-':
> return left - expression(); // read and evaluate an
> Expression,
> // then do a subtraction
> default:
> ts.unget(t);
> return left; // return the value of the Term
> }
> }
>
> int main()
> try
> {
> //while (cin) cout << expression() << '\n'; // version 0
> cout <<"Welcome to our simple calculator\n";
> cout << "Please enter-expression using floating-point
> expression\n";
> cout << "type = to print and x to exit\n";
>
> double val= 0; // version 1
> while (cin) {
> Token t = ts.get();
> if (t.kind == 'x') break;
> if (t.kind == '=')
> cout << val << '\n';
> else {
> ts.unget(t);
> val = expression();}
> }
> /*
> double val = 0; // version 2
> while (cin) {
> cout << "> ";
> Token t = ts.get();
> while (t.kind == ';') t=ts.get(); // eat ';'
> if (t.kind == 'q') {
> keep_window_open();
> return 0;
> }
> ts.unget(t);
> cout << "= " << expression() << endl;
> }
> */
> keep_window_open();
> return 0;
> }
> catch (runtime_error& e) {
> cerr << e.what() << endl;
> keep_window_open("~~");
> return 1;
> }
> catch (...) {
> cerr << "exception \n";
> keep_window_open("~~");
> return 2;
> }
>
>
> "Victor A. Wagner Jr." <[EMAIL PROTECTED]> wrote:
>
> At 15:06 2007-02-19, Robert Ryan wrote:
>
> does anyone have an idea
>
>
>
> /* "be-bugged" calculator: many syntax and type
> errors, just three logic
>
> errors (we hope).
>
> Our aim waw to be "medium devious"; that is, to
> provide errors that
>
> are not impossible to find, easy to fix once found,
> but
=== message truncated ===
_________________
Joseph A. Marrero
http://www.l33tprogrammer.com/
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