How to stop the current iteration and start the next iteration of the loop( for/while ) in skill?

The next() and break() functions are for the SKILL debugger. They are NOT equivalent to functions in other languages which continue to the next point in a loop, or break out of a loop. The go() function is a goto in SKILL. I've never used it, and have avoided it like the plague - I'm opposed to it on philosophical grounds (I think it has no place in a functional language).

There are several ways you can do loops which exit early. For example:

lst='(1 2 3 4 0 5 6 7)
forall(item lst
    when(errset(div=100.0/item)
        printf("100.0/%d is %g\n" item div)
        t
    )
)

Similarly you could use the exists() function to iterate over a list until a match is made. Or you could use a while loop, taking the cdr each time:

status=t
ptr=lst
while(status && ptr
   item=car(ptr)
   if(some_bad_condition then
     status=nil
   else
     ptr=cdr(ptr)
   )
)

Or if you want to use a jump-out type approach, you could use:

prog(()
  foreach(item lst
    if(errset(div=100.0/item) then
      printf("100.0/%d is %g\n" item div)
    else
      return()
    )
  )
)

The return is returning from the prog() - and although it happens in the middle of the foreach, it will jump out of the foreach cleanly. 

Personally I don't tend to like this approach, because it's a bit of a goto in disguise, and it's still smacks of "spaghetti programming" to me. But I can see that for some difficult to handle errors, it could be useful.

Regards,

Andrew.

The next() and break() functions are for the SKILL debugger. They are NOT equivalent to functions in other languages which continue to the next point in a loop, or break out of a loop. The go() function is a goto in SKILL. I've never used it, and have avoided it like the plague - I'm opposed to it on philosophical grounds (I think it has no place in a functional language).

There are several ways you can do loops which exit early. For example:

lst='(1 2 3 4 0 5 6 7)
forall(item lst
    when(errset(div=100.0/item)
        printf("100.0/%d is %g\n" item div)
        t
    )
)

Similarly you could use the exists() function to iterate over a list until a match is made. Or you could use a while loop, taking the cdr each time:

status=t
ptr=lst
while(status && ptr
   item=car(ptr)
   if(some_bad_condition then
     status=nil
   else
     ptr=cdr(ptr)
   )
)

Or if you want to use a jump-out type approach, you could use:

prog(()
  foreach(item lst
    if(errset(div=100.0/item) then
      printf("100.0/%d is %g\n" item div)
    else
      return()
    )
  )
)

The return is returning from the prog() - and although it happens in the middle of the foreach, it will jump out of the foreach cleanly. 

Personally I don't tend to like this approach, because it's a bit of a goto in disguise, and it's still smacks of "spaghetti programming" to me. But I can see that for some difficult to handle errors, it could be useful.

Regards,

Andrew.