BitArray in custom class initialize it in ctor with arguments
Hi! I need to use array of bits in my custom class. I tried to add std.bitmanip.BitArray as field, but got a strange error. What am I doing wrong? import std.bitmanip; class Scene { BitArray collisionMap; this(int w, int h) { collisionMap.init([0,0,0]); } } C:\D\dmd2\windows\bin\..\..\src\phobos\std\bitmanip.d line 606 Error: btr cannot be interpreted at compile time, because it has no available source code If I use collisionMap.length(w*h), I get: C:\D\dmd2\windows\bin\..\..\src\phobos\std\bitmanip.d line 554 Error: non-constant expression [0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, And if I use BitArray in default ctor ( this() ), or in other function in class, or in main function, all is OK. But I need only ctor with arguments that initialize the BitArray with '0' and sets 'w*h' length. DMD version 2.065.0 Sorry for bad English.
Re: Ranges/algorithms for aggregation
Luís Marques: It would swap elements, like sort, so it doesn't need to put them anywhere, just permute them. The advantage is this: Input: [7, 3, 7, 1, 1, 1, 1] Output sort: [1, 1, 1, 1, 3, 7, 7] Output groupSort: [3, 7, 7, 1, 1, 1, 1] I think to swap items it must know where to swap them to. And you can't do that efficiently if the groups are unsorted. Bye, bearophile
Re: BitArray in custom class initialize it in ctor with arguments
MarisaLovesUsAll: Hi! I need to use array of bits in my custom class. I tried to add std.bitmanip.BitArray as field, but got a strange error. What am I doing wrong? import std.bitmanip; class Scene { BitArray collisionMap; this(int w, int h) { collisionMap.init([0,0,0]); } } C:\D\dmd2\windows\bin\..\..\src\phobos\std\bitmanip.d line 606 Error: btr cannot be interpreted at compile time, because it has no available source code To me this program compiles: import std.bitmanip; class Scene { BitArray collisionMap; this(int w, int h) { collisionMap.init([0,0,0]); } } void main() {} Errors like btr cannot be interpreted at compile time mean that you are trying to run at compile-time something that can only run at run-time. So are you using enums or static immutables or static constructors or something like that? Bye, bearophile
Re: Ada-Style Range Types with Value Range Propagation in Arithmetic
Nordlöw: I cracked it: This is important stuff. So if you find that you can't do something in D, consider asking for it in the main D newsgroup and in Bugzilla. Bye, bearophile
Re: to! converting 1D to 2D array
On Friday, 14 March 2014 at 19:24:21 UTC, Chris Williams wrote: In D, an array is a struct (struct Array), with an address and a length value. A multi-dimensional array is an Array with an address pointing to an array of Arrays. So with an int[2][2] array, you have a layout like: @1000 Array(address=1016, length=2) @1016 [Array(address=1048, length=2),Array(address=1056, length=2)] @1048 [1,2] @1056 [3,4] This is not true; you need to distinguish between fixed-size and dynamically sized arrays. It's better to call the latter slices to avoid the confusion. Fixed-size arrays are value types, there are no references/addresses involved in storing them. So this: int[2][2] a; always has the following layout: @1000 [1,2] @1008 [3,4] You layout would be correct for this example: int[][] = [[1,2],[3,4]];
More updated question about Sleep/msleep/usleep
Hello, I know there are severel threads concerning Wait, Pause, Sleep, a.s.o but most of them were created in 2007 or similiar. It seems D has changed a lot because when I try to call sleep/msleep (example), the compiler cannot find it (ERROR: undefined indentifier). import std.stdio; /// other imports as well import std.c.time; main_bock() { init and things sleep(1); // not found std.c.time.sleep(2); // not found as well std.c.time.msleep(1000); // nope... /// continued code } So, is there a newer version? I get a hint for thread.sleep but this may be a member function. Also, i suppose I MAY use Sleep() from windows.h, if there is no other option.
Re: More updated question about Sleep/msleep/usleep
import core.thread; void main() { }
Re: More updated question about Sleep/msleep/usleep
This will work: import core.thread; void main() { Thread.sleep(5.seconds); } sleep is a member of Thread, but it is static so you can easily call it to sleep the current thread. The argument is a Duration, which is most easily constructed with the .seconds, .msecs, .minutes, etc. helper functions like I did here.
Re: Function to print a diamond shape
The computation times of different methods can differ a lot. How do you suggest to measure this effectively without the overhead of the write and writeln output? Would a count of 11 and stubs like below be reasonable, or would there be something else that would prevent the optimizer from getting too aggressive? void writelnx(T...)(T args) { } void writex(T...)(T args) { }
shouldn't this work? / how to make it work?
pls see example code below. the two 'test' templates work fine by themselves. if, however, in the same module, the eponymous template does not work anymore. instead the compiler seems to try instantiating the variadic template. a) why? for how i understand it, this should not happen as o they have very different signatures, i.e. completely incompatible argument lists ( zero vs 1 arguments) o the string parameter is more specialized than the take-all tuple b) how can i make it work? cheers, det CODE: = import std.stdio; // cannot be used with function arguments template test(string str ){ enum test = template 'test' used with ~str; } // cannot be called with less than 2 function arguments string test (T ...)( T strs ) if( 1strs.length ) { return templated function 'test' called with ~strs[0]~ and ~strs[1]; } // enum epo = test!one; // use eponymous template // if commented in: // Error: tuple T is used as a type // in line 9 = string test (T ...)( T strs ) enum vari = test(two, three); // use templated/variadic function void main(string[] args) { // writeln( epo ); writeln( vari ); }
Re: shouldn't this work? / how to make it work?
On Saturday, 22 March 2014 at 22:54:15 UTC, captaindet wrote: pls see example code below. the two 'test' templates work fine by themselves. if, however, in the same module, the eponymous template does not work anymore. instead the compiler seems to try instantiating the variadic template. a) why? for how i understand it, this should not happen as o they have very different signatures, i.e. completely incompatible argument lists ( zero vs 1 arguments) o the string parameter is more specialized than the take-all tuple b) how can i make it work? cheers, det CODE: = import std.stdio; // cannot be used with function arguments template test(string str ){ enum test = template 'test' used with ~str; } // cannot be called with less than 2 function arguments string test (T ...)( T strs ) if( 1strs.length ) { return templated function 'test' called with ~strs[0]~ and ~strs[1]; } // enum epo = test!one; // use eponymous template // if commented in: // Error: tuple T is used as a type // in line 9 = string test (T ...)( T strs ) enum vari = test(two, three); // use templated/variadic function void main(string[] args) { // writeln( epo ); writeln( vari ); } Looks like a bug to me. By the way, the variadic template is eponymous, too: The template declares a function with the same name.
Re: Function to print a diamond shape
I decided to redirect stdout to nul and print the stopwatch messages to stderr. So, basically like this. import std.stdio; import std.datetime; import std.cstream; StopWatch sw; sw.start(); measured code sw.stop(); derr.writefln(time: , sw.peek().msecs, [ms]); Then, windows results comparing two versions, this for n=2001, shows one form is about 3x faster when you redirect stdout to nul. D:\diamond\diamond\diamond\Releasediamond 1nul time: 15[ms] time: 42[ms]
Re: Function to print a diamond shape
On 03/22/2014 06:03 PM, Jay Norwood wrote: derr.writefln(time: , sw.peek().msecs, [ms]); Cool. stderr should work too: stderr.writefln(/* ... */); Ali