========================
Function for the Scanner
========================

Now comes a major change:

- The code within the `while` loop is moved to a function named `getToken`.
- All variables are now global, and there is an additional variable called
  `token`. This variable is overwritten every time something interesting is
  found in the input, such as being set to `1` for an integer, `2` for a plus,
  etc.
- In `main`, `getToken` is called in a loop, and the value of `token` is
  printed.  The loop exits when `token` has the value `7`, indicating that
  `getToken` has encountered an `EOF`.

---- CODE(file=session01/page07/ex1.abc,type=abc,linenumbers) ------------------
@ <stdio.hdr>

global token: int = 0;
global ch: int = 0;
global val: int = 0;

fn getToken()
{
    if (ch >= '0' && ch <= '9') {
        val = 0;
        while (ch >= '0' && ch <= '9') {
            val = val * 10;
            val = val + ch - '0';
            ch = getchar();
        }
        printf("integer with value %d\n", val);
        token = 1;
    } else if (ch == '+') {
        printf("PLUS\n");
        ch = getchar();
        token = 2;
    } else if (ch == '*') {
        printf("ASTERISK\n");
        ch = getchar();
        token = 3;
    } else if (ch == ';') {
        printf("SEMICOLON\n");
        ch = getchar();
        token = 4;
    } else if (ch == '(') {
        printf("LPAREN\n");
        ch = getchar();
        token = 5;
    } else if (ch == ')') {
        printf("RPAREN\n");
        ch = getchar();
        token = 6;
    } else if (ch == EOF) {
        token = 7;
    } else {
        printf("ch = %d -> '%c'\n", ch, ch);
        ch = getchar();
        token = 8;
    }
}

fn main()
{
    while (true) {
        getToken();
        if (token == 7) {
            break;
        } else if (token == 1) {
            printf("token = %d, val = %d\n", token, val);
        } else {
            printf("token = %d\n", token);
        }
    }
}
--------------------------------------------------------------------------------

Tasks
=====
- For now, let's not worry about the sense or nonsense of this change. First,
  let's practice our copy-and-paste skills and using our text editor. Don't copy
  and paste the above code, apply the changes manually.

- Insert the following code after line 52:

  ---- CODE(type=abc) ----------------------------------------------------------
  53         } else if (token == 1) {
  54             printf("token = %d, val = %d\n", token, val);
  ------------------------------------------------------------------------------

- Remove all lines containing printf in getToken.