OpenEuphoria

2. Re: request for source change

• Posted by Pete Lomax <petelomax at blueyonder.co.uk> Jun 05, 2007
• 505 views

Bernie Ryan wrote:
> 
> 
> How about doing away with the short-circuit warning message.
> The warning is a pain in the neck.
> Why should a user have to :
> 1. Rewrite their code.
> 2. Place without warning around their code.
> Please don't suggest placing without warning at the top of my program.
> 
> After all short-circuit code is not a bad programming practice and
> some times is desired.
> 
> At least you could have a without short_circuit_warning option.

Just get rid of it. This utterly pointless and extremely annoying warning does
not even work properly anyway:

integer id id=0
function f() id=3 return id end function
function g(integer i) return i end function
    if id or f()=0 then end if
    if id or g(0) then end if
    if id or g(f()) then end if

You only get a warning on the first if statement, and none if you comment that
one line out, despite the fact that the self same f() can just as easily be
short-circuited on the third if statement. Which as I have also pointed out is
NOT to be taken as encouragement to make matters worse.

Anyway, it looks pretty easy to remove, ~line 442 in parser.e

Regards
Pete

4. Re: request for source change

• Posted by Pete Lomax <petelomax at blueyonder.co.uk> Jun 06, 2007
• 494 views

Robert Craig wrote:
> I don't agree that this warning is "utterly pointless".
So I gathered 
> It was important at the time that Euphoria switched over
> to short-circuit evaluation, in order to help spot subtle
> errors in now-broken old code,
Maybe, in 1999, but I was not around here then.
> and it still has some 
> value in the rare situation where a function with side-effects
> might be skipped.
Do you have any convincing example where that is so?
> 
> Perhaps what we need is a way to suppress specific warnings.
> For example, if you get a short-circuit warning and you determine
> that it's a harmless situation, you could say something like:
> 
>    without warning "short-circuit"
> 
> or in general,
> 
>    without warning "string of chars"
> 
> where any warnings that contain the specified string
> will be suppressed (according to the usual scope of
> without warning, which is limited to the file it appears
> in, from that point forward, and any included files.)
>
> If you specify multiple without warning statements,
> a list of filter strings will be maintained by the front end. 
> Later, when you say:
>    with warning
> all warnings will be enabled. Or perhaps you could
> specifically say:
>    with warning "short-circuit" 
> or 
>    with warning "not used"
> etc.
> This would help document for others, which specific 
> warnings you are suppressing, and in which parts of
> your program.
> 
> I would go along with something like this, if someone else is willing 
> to implement it, and no one has any better idea, or serious
> objections. (But not for 3.1 - it's too late.)

OK, for 3.1.1, add the following to parser.e, ~line 1663:

elsif equal(option, "warning") then
	OpWarning = on_off
	tok=next_token() 
	if tok[T_ID]!=STRING then
	    putback(tok)
	    updateWarningSkipList(0,on_off)
	else
	    updateWarningSkipList(tok[T_SYM],on_off)
	end if

(admittedly using next_token() for this uses up an extra symtab entry)
and to error.e, ~line 26:

sequence wSkip
	 wSkip={}

global procedure updateWarningSkipList(object mstr, boolean flag)
integer k
    if mstr!=0 then
	mstr = SymTab[mstr][S_OBJ]
    end if

    if atom(mstr) or length(mstr)=0 then
	wSkip={}
    else
	OpWarning=TRUE
	k=find(mstr,wSkip)
	if flag then			    -- with warning "xxx"
	    if k then
		wSkip=wSkip[1..k-1]&wSkip[k+1..$]
	    end if
	else				    -- without warning "xxx"
	    if not k then
		wSkip=append(wSkip,mstr)
	    end if
	end if
    end if
end procedure

global procedure Warning(sequence msg)
-- add a warning message to the list
    sequence p
    
    if OpWarning then
	for i=1 to length(wSkip) do
	    if match(wSkip[i],msg) then return end if
	end for
	... as before

Works fine as far as I can tell, and treats

with warning ""
without warning ""

as if the "" were not present.

Regards,
Pete

6. Re: request for source change

• Posted by Robert Craig <rds at RapidEuphoria.com> Jun 06, 2007
• 510 views

Pete Lomax wrote:
> I wrote:
> > 
> > Robert Craig wrote:
> > > (according to the usual scope of
> > > without warning, which is limited to the file it appears
> > > in, from that point forward, and any included files.)
> Ah, I forgot that. I assume it is just a trivial save/restore of wSkip in
> IncludePush()/IncludePop(),
> and obviously I have not tested that.

If you register with SourceForge, I'll give you full 
developer access. Then you can check out official source, 
add this change, test it well, and check the new source back in. 
It's pretty easy using TortoiseSVN for Windows.
You can also document the change, or leave that up to me.
You could start anytime, but it might be better
to wait until 3.1 is officially done and checked in.

Regards,
   Rob Craig
   Rapid Deployment Software
   http://www.RapidEuphoria.com