OpenEuphoria

Re: Return from nested subroutines (still goto discussion)

• Posted by Ferlin Scarborough <ferlin1 at bellsouth.net> Nov 12, 2004
• 516 views

Enough with the goto's already....I did not mean to open a can of worms when
I said I would not use them and did not care for them.  We had this discussion
in depth 4 or 5 years ago, no use in rehasing old ground.

Here is a couple of messages from Robert Craig from the past.

>Date:         Mon, 15 Nov 1999 18:06:48 -0500
>From:         Robert Craig <rds at ATTCANADA.NET>
>Subject:      Goto
>
>Since some people think I should come out of hiding
>and voice an opinion on language design proposals,
>here's my current thinking about goto.
>
>1. completely general goto, including jumps
>    between routines: 0% chance
>
>2. goto within a routine: 0.01% chance
>
>3. specialized goto to break out of nested loops: 1% chance
>
>I'm not religiously opposed to goto's. There are some
>goto's coded into the C source of the interpreter, and
>at one point in the early days I even had one of the
>"between routines" gotos that are possible in C using
>setjmp()/longjmp(). It proved to be nightmarishly hard
>to understand and maintain so I took it out.
>
>I agree that a specialized goto (or special "exit")
>to get out of a nested loop is probably less clumsy
>than setting up artificial state variables. I just don't think
>that this occurs often enough, or causes enough pain
>to warrant a new language feature, such as labelled
>statements and a special kind of exit.
>
>The normal sort of gotos, that let you jump around within
>a routine are like cigarettes. One or two, once in a while,
>will not harm you. The trouble is they become addictive.
>If you never start using them, you will never have a craving
>for one.
>
>When I had to maintain code written by someone
>else, the sight of a heavily goto'd section of code would
>really be discouraging. The guy who wrote the goto's
>probably had some idea of what the control-flow was
>supposed to be, but I had to struggle to get the
>same picture into my head. Standard control-flow
>statements, like for..end for, if-elsif-else etc are much
>easier to digest and reason about.
>
>Regards,
>     Rob Craig
>     Rapid Deployment Software
>     http://www.RapidEuphoria.com
>
> 
>Date:         Sat, 10 Jun 2000 11:59:11 -0400
>From:         Robert Craig <rds at ATTCANADA.NET>
>Subject:      Re: (Fwd) Re: compiler?? step 4
>
>Kat writes:
>> another repost, no answer recieved again.....
>
>Rob Craig writes:
>>> Extra temp variables
>>> are used where needed, and all control-flow
>>> constructs are reduced to goto's.
>
>Kat writes:
>> Oh goodie, goto's!!  )
>> Can we use them in the Eu code before compiling too?
>
>Sorry, because of your smiley I didn't think this was a serious
>question. No, goto's will not be allowed in Euphoria.
>The compiler generates them because it is mapping
>from the low-level intermediate language into C.
>In the intermediate language (used by both the interpreter
>and the compiler) control-flow has already been
>broken down into goto's.
>
>Rob Craig writes:
>>>You can see
>>> the original Euphoria statement as a C comment,
>>> followed by the C statements that implement that
>>> Euphoria statement.
>
>Kat writes:
>>Hmm,,, sounds like you'll be giving away the store with that one.
>
>Yes, some very interesting information will be revealed.
>However there is still a lot of information that won't be
>revealed. I think it's worth the risk.
>
>Regards,
>   Rob Craig
>   Rapid Deployment Software
>   http://www.RapidEuphoria.com
>
>

So, there you have it, the GOD or CREATOR of Euphoria has spoken, and the
result is:
  "No, goto's will not be allowed in Euphoria."

So, let's not beat a dead dog to death.....

Later.

Ferlin Scarborough

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