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std.math.pow brokeness

 
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prefetch



Joined: 13 Aug 2005
Posts: 6
PostPosted: Mon Aug 15, 2005 8:03 am    Post subject: std.math.pow brokeness Reply with quote
D seems like a great language and all, but this seems broken to me. any ideas on why this doesn't work?

import std.math;

int main() {
int myint;
myint = pow(2,16);
}

rand.d(5): function std.math.pow called with argument types:
(int,int)
matches both:
std.math.pow(real,uint)
and:
std.math.pow(real,real)
rand.d(5): cannot implicitly convert expression (pow(2,16)) of type real to int
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jcc7



Joined: 22 Feb 2004
Posts: 657
Location: Muskogee, OK, USA
PostPosted: Mon Aug 15, 2005 11:31 am    Post subject: Re: std.math.pow brokeness Reply with quote
prefetch wrote:
myint = pow(2,16);
You should be able to get it to work to with something like
Code:
myint = pow(2.0L,cast(uint)16)
(according to http://www.digitalmars.com/d/archives/digitalmars/D/14534.html).
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prefetch



Joined: 13 Aug 2005
Posts: 6
PostPosted: Mon Aug 15, 2005 12:01 pm    Post subject: Re: std.math.pow brokeness Reply with quote
jcc7 wrote:
prefetch wrote:
myint = pow(2,16);
You should be able to get it to work to with something like
Code:
myint = pow(2.0L,cast(uint)16)
(according to http://www.digitalmars.com/d/archives/digitalmars/D/14534.html).


thanks.

this is how it worked out:

import std.math;
int main() {
real myreal = pow(2.0L, cast(uint)3);
printf("?d\n",cast(int)myreal);
return 0;
}

let me complain a little bit here. this seems like an enormous amount of effort to print out what should be: printf("?d",pow(2,3));

what's up with this lameness? also, finding any reasonably good docs in this language is a nightmare. this is too bad, because i like the concepts of this language, but the docs just suck.

for example, i found some sample code with the function "Sleep" in it - but it wouldnt compile, so i started looking around for docs on the Sleep function. umm...still looking...

holy crap, shouldn't there be a freaking index of functions for the runtime lib? Mad
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JJR



Joined: 22 Feb 2004
Posts: 1104
PostPosted: Mon Aug 15, 2005 2:16 pm    Post subject: Reply with quote
Your frustration is well-founded, I agree.

I'm pretty sure problems like this have been reported before. I suggest you go to the main d newsgroup and look through the posts there. If you can't find complaints/responses of a similar nature, make a post describing the issue on the bugs newsgroup.

Dsource is a good place for learning and connecting with other d developers, but it's not a effective medium for getting D language issues fixed (if that's your intention). You need to get the language designer's attention in that regard.

That said, I can sympathize with how you feel. That certainly looks to be silly phobos library issue.

-JJR
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pragma



Joined: 28 May 2004
Posts: 607
Location: Washington, DC
PostPosted: Mon Aug 15, 2005 5:15 pm    Post subject: Re: std.math.pow brokeness Reply with quote
prefetch wrote:
what's up with this lameness? also, finding any reasonably good docs in this language is a nightmare. this is too bad, because i like the concepts of this language, but the docs just suck.

for example, i found some sample code with the function "Sleep" in it - but it wouldnt compile, so i started looking around for docs on the Sleep function. umm...still looking...

holy crap, shouldn't there be a freaking index of functions for the runtime lib? Mad


I agree with you completely. I cringe every time I have to sift through the Phobos docs. Its obviously hurting D's adoption rate pretty badly.

If it helps, I think part of the problem is due to D being fostered broadly by hard-core hackers some of which have been working with D for years now; we're used to bad documentation and doing things the hard way. While this is no excuse, I think it explains the lack of negative feedback to Walter regarding the state of the DigitalMars D site.

I would *strongly* recommend putting your $0.02 up on the D news group, if you haven't already. There are some others who have set up external documentation sites, so you may likely find other D-philes who feel the same way (which will likely be everybody) with whom you can improve the situation. Smile

Even though Walter has control of the language spec, and is developing the reference compiler, *everything else* is open. Since that's where his focus is, everything else imaginable comes a distant second with respect to the overall state of affairs. So its ultimately down to us to improve the state of D everywhere else that we can, through and beyond a 1.0 release.
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Derek Parnell



Joined: 22 Apr 2004
Posts: 408
Location: Melbourne, Australia
PostPosted: Mon Aug 15, 2005 10:01 pm    Post subject: Re: std.math.pow brokeness Reply with quote
prefetch wrote:


this is how it worked out:

import std.math;
int main() {
real myreal = pow(2.0L, cast(uint)3);
printf("?d\n",cast(int)myreal);
return 0;
}

let me complain a little bit here. this seems like an enormous amount of effort to print out what should be: printf("?d",pow(2,3));



This is how I would do it
Code:

import std.math;
import std.stdio;

int main() {
 writefln("?s", pow(2.0L,16U));
 return 0;
}


prefetch wrote:
what's up with this lameness? also, finding any reasonably good docs in this language is a nightmare. this is too bad, because i like the concepts of this language, but the docs just suck.

for example, i found some sample code with the function "Sleep" in it - but it wouldnt compile, so i started looking around for docs on the Sleep function. umm...still looking...

holy crap, shouldn't there be a freaking index of functions for the runtime lib? Mad


Yep! The documentation is poor.
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skype name: derek.j.parnell
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aldacron



Joined: 05 May 2004
Posts: 1322
Location: Seoul, South Korea
PostPosted: Mon Aug 15, 2005 10:27 pm    Post subject: Re: std.math.pow brokeness Reply with quote
prefetch wrote:

for example, i found some sample code with the function "Sleep" in it - but it wouldnt compile, so i started looking around for docs on the Sleep function. umm...still looking...


There is no Sleep function in D. I'm guessing that the code you refer to was from a Windows program and, if so, Sleep is a Win32 API function. Sleep halts execution of the current thread for the specified number of milliseconds. It is typically used to induce delays in program execution for one reason or another. Another common use is 'yielding' the time slice. If you look in the Phobos source for std.thread, you will see that the Thread.yield method is implemented as Sleep(0) on Windows, which effectively gives up the remainder of the current thread's time slice so that other threads (processes) can execute.
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prefetch



Joined: 13 Aug 2005
Posts: 6
PostPosted: Tue Aug 16, 2005 7:40 am    Post subject: Reply with quote
so i did a grep in the phobos 'source' and found sleep in time.d, and so that made me happier.

thanks for the feedback folks. i think i'll post a general "wtf" to the newsgroup (which has no search feature on it (at least the web one from the d site), so it's not very usable..)

i'll probably also post something about how broken the thread section of phobos seems to be as well. argh...i *really* want to use this language for a production system and have my engineering team learn it - but it's not making it easy.

btw - derek, thanks for the POW foo, that is much easier...of course, i'm not sure how i was supposed to divine that solution from the docs. it'd be nice to have that little sample you wrote in the phobos docs.
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sean



Joined: 24 Jun 2004
Posts: 609
Location: Bay Area, CA
PostPosted: Tue Aug 16, 2005 10:24 am    Post subject: Re: std.math.pow brokeness Reply with quote
aldacron wrote:
There is no Sleep function in D. I'm guessing that the code you refer to was from a Windows program and, if so, Sleep is a Win32 API function. Sleep halts execution of the current thread for the specified number of milliseconds. It is typically used to induce delays in program execution for one reason or another. Another common use is 'yielding' the time slice. If you look in the Phobos source for std.thread, you will see that the Thread.yield method is implemented as Sleep(0) on Windows, which effectively gives up the remainder of the current thread's time slice so that other threads (processes) can execute.

std.thread should include a static 'sleep' function as well. Ares certainly has one.
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