'goto" gone from computer languages or is it!

[Dwight K. Elvey]

>From: "Allison" <ajp166 at bellatlantic.net>
>
>>
>>Subject: Re: 'goto" gone from computer languages or is it!
>>   From: "Dwight K. Elvey" <dwight.elvey at amd.com>
>>   Date: Thu, 12 May 2005 10:37:19 -0700 (PDT)
>>     To: cctalk at classiccmp.org
>>
>>Hi
>> I'd suspect that most didn't like the goto
>>because it becomes hard to implement in a structured
>>language. Things like random nesting of subroutines and
>>then goto's to various points can make things really
>>messed up. There are also the problems of allocated
>>memory. Do you keep it or clean it?
>
>Often reading it is the challenge.  Goto within a subroutine
>usually reads fine.  Its when there are subs within Loop/whiles
>get mixed with gotos.  It's more about readability.  Old basic 
>was bad as often people were also cramped for space (especially
>interpreted basics.).
>
>> Many think of goto as being similar to jmp in assembly.
>
>It is.
>
>>Actually in a high level language, it is more complicated
>>than that. The language tend to lead one to think they
>>can use it just anywhere. In assembly, you are more
>>conscious ( or should be ) of thing like stack depth
>>and allocated space, since you explicitly handle these
>>things.
>
>You seem to confuse JMP/Jump/goto with Call/JMS/GOSUB as only
>the latter affects the stack (in asm).

Hi
 I have no confusion, I meant that jmp instruction does
not effect the stacks, for good or bad. It is that most
high level languages hide the stack actions giving
the false impression that one can goto anywhere. In
assembly, one keeps track of such stuff themselves
so they don't get into such trouble.

>
>In assembly you often have jumps as a result of branch conditions 
>In some cpus the logic is actully skip next instuction on condition.
>in basic the conditional is IF xx then Goto YYYY (some allow operations.).
>The computed goto is only a replacement for SWITCH or IF THEN trees
>and a improvement over the latter.

 else is a jmp. A computed goto is usually done from a table
lookup in assembly although I've seen it done directly for
interupt vectors.
Dwight

 
>
>In the end GOTO is not bad, it is random stringy pasta code that can 
>result from misuse.
>
>
>Allison
>
>