sscanf

/*----------------------------------------------------------------------------*-
Function:
    sscanf
Params:
    string[] - String to extract parameters from.
    format[] - Parameter types to get.
    {Float,_}:... - Data return variables.
Return:
    0 - Successful, not 0 - fail.
Notes:
    A fail is either insufficient variables to store the data or insufficient
    data for the format string - excess data is disgarded.

    A string in the middle of the input data is extracted as a single word, a
    string at the end of the data collects all remaining text.

    The format codes are:

    c - A character.
    d, i - An integer.
    h, x - A hex number (e.g. a colour).
    f - A float.
    s - A string.
    z - An optional string.
    pX - An additional delimiter where X is another character.

    Now has IsNumeric integrated into the code.

    Added additional delimiters in the form of all whitespace and an
    optioanlly specified one in the format string.
-*----------------------------------------------------------------------------*/

stock sscanf(string[], format[], {Float,_}:...)
{
    if (isnull(string))
    {
        return format[0];
    }
    new
        formatPos = 0,
        stringPos = 0,
        paramPos = 2,
        paramCount = numargs(),
        delim = ' ';
    while (paramPos < paramCount && string[stringPos])
    {
        switch (format[formatPos++])
        {
            case '\0':
            {
                return 0;
            }
            case 'i', 'd':
            {
                new
                    neg = 1,
                    num = 0,
                    ch = string[stringPos];
                if (ch == '-')
                {
                    neg = -1;
                    ch = string[++stringPos];
                }
                do
                {
                    stringPos++;
                    if (ch >= '0' && ch <= '9')
                    {
                        num = (num * 10) + (ch - '0');
                    }
                    else
                    {
                        return -1;
                    }
                }
                while ((ch = string[stringPos]) > ' ' && ch != delim);
                setarg(paramPos, 0, num * neg);
            }
            case 'h', 'x':
            {
                new
                    ch,
                    num = 0;
                while ((ch = string[stringPos]) > ' ' && ch != delim)
                {
                    switch (ch)
                    {
                        case 'x', 'X':
                        {
                            num = 0;
                            continue;
                        }
                        case '0' .. '9':
                        {
                            num = (num << 4) | (ch - '0');
                        }
                        case 'a' .. 'f':
                        {
                            num = (num << 4) | (ch - ('a' - 10));
                        }
                        case 'A' .. 'F':
                        {
                            num = (num << 4) | (ch - ('A' - 10));
                        }
                        default:
                        {
                            return -1;
                        }
                    }
                }
                setarg(paramPos, 0, num);
            }
            case 'c':
            {
                setarg(paramPos, 0, string[stringPos++]);
            }
            case 'f':
            {
                setarg(paramPos, 0, _:floatstr(string[stringPos]));
            }
            case 'p':
            {
                delim = format[formatPos++];
                continue;
            }
            case 's', 'z':
            {
                new
                    i = 0,
                    ch;
                if (format[formatPos])
                {
                    while ((ch = string[stringPos++]) && ch != delim)
                    {
                        setarg(paramPos, i++, ch);
                    }
                    if (!i)
                    {
                        return -1;
                    }
                }
                else
                {
                    while ((ch = string[stringPos++]))
                    {
                        setarg(paramPos, i++, ch);
                    }
                }
                stringPos--;
                setarg(paramPos, i, '\0');
            }
            default:
            {
                continue;
            }
        }
        while (string[stringPos] && string[stringPos] != delim && string[stringPos] > ' ')
        {
            stringPos++;
        }
        while (string[stringPos] && (string[stringPos] == delim || string[stringPos] <= ' '))
        {
            stringPos++;
        }
        paramPos++;
    }
    while (format[formatPos] == 'z') formatPos++;
    if (format[formatPos] > ' ') return format[formatPos];
    return 0;
}