OpenEuphoria

Re: Rob: Out of memory + broken shorthand assignment operators in expressions

• Posted by Robert Craig <rds at RapidEuphoria.com> Nov 18, 2005
• 456 views

Vincent wrote:
> This is quite interesting because I've written small programs 
> simular to that, and Euphoria runs out of memory (every time) 
> at loop 141441051. I didnt think of reporting it, because I 
> thought my computer was running out of memory. Adjusting the 
> swap file size did nothing.
>
> My computer is a 2.66 GHz Pentium 4 Northwood 512 KB L2 cache; 
> 512 MB DDR SD-RAM @ 333 MHz; 512 MHz front-side bus; Windows XP 
> SP 2.

Hmm...  141441051 x 4 bytes per element = 565,764,204 bytes
which already exceeds your RAM. Plus where is the O/S
supposed to reside? Plus append() must sometimes make a full
copy of your sequence plus extra, when it moves the data 
to a new larger contiguous block.

> I discovered an issue that has to do with assignment operators 
> failing to work in conditional or loop expressions. My guess 
> is that this been a issue since they were introduced in 
> Euphoria v2.1.
> 
> For example:
> }}}
<eucode>
> -- this code runs
> integer i, f
> 
> i = 0
> f = 0
> 
> if i = i + 1 then
> end if
> 
> while f = f + 1 do
> end while
> 
> machine_proc(26,0) -- wait_key
> </eucode>
{{{

> But...
> }}}
<eucode>
> -- this code fails with an error
> integer i, f
> 
> i = 0
> f = 0
> 
> if i += 1 then
> end if
> 
> while f += 1 do
> end while
> 
> machine_proc(26,0) -- wait_key
> </eucode>
{{{

> 
> The same thing happens with -=, /=, *=, and 
> &= (with sequences).

f += 1 is not an expression. It's a statement.
That's why you get an error message.

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