Path: utzoo!mnetor!uunet!husc6!wjh12!maynard!campbell
From: campbell@maynard.BSW.COM (Larry Campbell)
Newsgroups: comp.lang.c
Subject: Re: gotos
Message-ID: <1075@maynard.BSW.COM>
Date: 22 Apr 88 14:30:47 GMT
References: <1988Apr8.183815.3187@utzoo.uucp> <449@goofy.megatest.UUCP> <1988Apr11.201934.20594@utzoo.uucp> <748@l.cc.purdue.edu> <3470@bunker.UUCP> <2200@louie.udel.EDU>
Reply-To: campbell@maynard.UUCP (Larry Campbell)
Organization: The Boston Software Works, Inc.
Lines: 56

In article <2200@louie.udel.EDU> new@udel.EDU (Darren New) writes:
<>How about: (pseudocode)
<>   for (i = 0; i < max_in_table && key != name[i]; ++i) 
<>      if (keypressed()) goto handle_key;
<>   seek(helpfile, offset[i]);
<>   if (keypressed()) goto handle_key;
<>   linecount = 0;
<>   do {
<>      read_line_from_file();
<>      ++linecount;
<>      if (keypressed()) goto handle_key;
<>      if (read_line[0] == special_flag_char) goto handle_key;
<>      insert_spaces_and_color_codes();
<>      if (keypressed()) goto handle_key;
<>      display_text_line();
<>      if (keypressed()) goto handle_key;
<>      } while (linecount < 24);
<>   handle_key:
<>   c = wait_for_key_then_read_it();
<>   switch (c) {
<>      case 'A': ...
<>       ...
<>      }

Use a signal handler.  Example:

handle_key()
{
c = wait_for_key_then_read_it();
switch (c)
    {
    case 'A': ...
      ...
    }
}

... main body of code:

    signal(SIGIO, handler);
    for (i = 0; i < max_in_table && key != name[i]; ++i) 
        ;
    seek(helpfile, offset[i]);
    linecount = 0;
    do {
        read_line_from_file();
        ++linecount;
        insert_spaces_and_color_codes();
        display_text_line();
        } while (linecount < 24);

This is not only much clearer and easier to read, it's also considerably
faster.  And doesn't use gotos.
-- 
Larry Campbell                                The Boston Software Works, Inc.
Internet: campbell@maynard.bsw.com          120 Fulton Street, Boston MA 02109
uucp: {husc6,mirror,think}!maynard!campbell         +1 617 367 6846