Re: Re: GMP and empty()

Hi, On Mon, Dec 30, 2013 at 12:59 PM, Yasuo Ohgaki <yohgaki@ohgaki.net> wrote: > Hi all, > > I thought GMP object does not work with math functions, but some of them > work. > Apparently, I was only testing with function that does not work with GMP. > Some math function > works. e.g. pow() with small value. min()/max() seems ok. > > Not only empty(), but there are number of wired behavior with GMP and > functions. > > I haven't tried them all, but we need to work more for these. > It seems time to write more tests and fix issues. > > === pow() === > [yohgaki@dev php-src]$ ./php-bin -d error_reporting=-1 -r '$v = > gmp_init("2"); var_dump(pow($v, 10));' > int(1024) > > This works fine. > > [yohgaki@dev php-src]$ ./php-bin -d error_reporting=-1 -r '$v = > gmp_init("223423"); var_dump(pow($v, 234242));' > float(INF) > > This returns float(INF). It may be acceptable. Returning GMP object with > correct value is better. > > [yohgaki@dev php-src]$ ./php-bin -d error_reporting=-1 -r '$v = > gmp_init("223423423423423423423422342342342342.234234234"); > var_dump(pow($v, 234242));' > int(0) > > but this returns int(0). > === round()/floor()/ceil()=== > > [yohgaki@dev php-src]$ ./php-bin -d error_reporting=-1 -r '$v = > gmp_init("25.234242342"); var_dump(round($v));' > float(0) > > It should be 25. floor()/ceil() is the same. > > ===abs()=== > > [yohgaki@dev php-src]$ ./php-bin -d error_reporting=-1 -r '$v = > gmp_init("25.234242342"); var_dump(abs($v));' > int(0) > > It returns int(0). > > > ===acos()=== > [yohgaki@dev php-src]$ ./php-bin -d error_reporting=-1 -r '$v = > gmp_init("25.234242342"); var_dump(acos($v), acos(25.234242342));' > float(1.5707963267949) > float(NAN) > > Something wrong. > > ===cos()=== > [yohgaki@dev php-src]$ ./php-bin -d error_reporting=-1 -r '$v = > gmp_init("25.234242342"); var_dump(cos($v), cos(25.234242342));' > float(1) > float(0.99485318302495) > > Almost correct, but it's not. > This is because gmp_init() yields bool(false) if you pass a floating point value, as it should because it's meant for arbitrary-length **integers** ;-) > > If GMP integer is passed, it raises E_WARNING. > > [yohgaki@dev php-src]$ ./php-bin -d error_reporting=-1 -r '$v = > gmp_init("2"); var_dump(cos($v), cos(2));' > Warning: cos() expects parameter 1 to be double, object given in Command > line code on line 1 > NULL > float(-0.41614683654714) > > ===log=== > [yohgaki@dev php-src]$ ./php-bin -d error_reporting=-1 -r '$v = > gmp_init("2"); var_dump(log($v), log(2));' > Warning: log() expects parameter 1 to be double, object given in Command > line code on line 1 > NULL > float(0.69314718055995) > > [yohgaki@dev php-src]$ ./php-bin -d error_reporting=-1 -r '$v = > gmp_init("2.2"); var_dump(log($v), log(2.2));' > float(-INF) > float(0.78845736036427) > > > Something wrong. > You could argue that it would make sense to cast GMP to a native integer or float type, but it will most likely lose precision; otherwise, what would be the point of using GMP in the first place? > > -- -- Tjerk