🚀 go-pugleaf

In article <4hv065$jao@solutions.solon.com>,
Konrad Schwarz <schwarz@a2.complang.tuwien.ac.at> wrote:
 >In article <4hqef9$1oj@solutions.solon.com>, hrubin@stat.purdue.edu (Herman Rubin) writes:
 >|> Question 1.  Is there a quick way of using a variable label?
 >|> The way it would be used is to identify the label to which one
 >|> wants to transfer, and then have some other place or places 
 >|> transfer to that point?  Transfers, loads, and stores take a
 >|> significant part of the running time of the algorithm, and
 >|> so something like setjmp and longjmp are to be avoided.
 >
 >An approach in ANSI C: use a giant switch statement inside of an endless loop
 >and program something similar to a finite-state machine.  Map labels to
 >integers, use a integer variable as the controlling expression of the switch
 >statement, and when you want to use a goto, assign the number of the
 >appropriate label to the integer variable and jump to the switch statement.
 >
 >For example:
 >
 >	register label = 0;
 >dispatch: switch (label) {
 >	case 10:
 >		do_something;
 >		label = 12;
 >		goto dispatch;
 >	...
 >	}
 >	
 >The disadvantage is that twice as many jumps are performed.

Which might be easier coded as

int label = 0;
while (1) {
    switch (label) {
    case 10:
	do_something();
	label = 12;
	continue;
    ...
    }
}

sl14@cornell.edu
Witty .sig under construction.