Re: Raw Binary into the console
On 07/11/2014 10:56 PM, Sean Campbell wrote:
> How Can I Print Raw Binary Into The Console?
Taking a step back, a D program prints to stdout, not console. However,
in most cases a D program's output ends up on the console when it is
started in a console.
So, one can print any byte value to the stdout, which usually ends up on
the console. Now, the question is how that value will be interpreted by
the console. On some consoles (e.g. Linux) the byte stream is
interpreted as a UTF-8 stream or a control character in the case of 0b011.
> I Have Variable Of Type ubyte which equals 0b011 How Can I Get The
> Variable To Print Out As 011
That is different though. You seem to want to print the value 0b011 as
the string "011". %b format specifier does that. However, in most cases
it is also useful to zero-pad the output:
writefln("%08b", 0b011);
Ali
Raw Binary into the console
How Can I Print Raw Binary Into The Console? I Have Variable Of Type ubyte which equals 0b011 How Can I Get The Variable To Print Out As 011
Re: I don't get it. version(unittest) can't seem to use local variable
On 07/11/2014 10:08 PM, dysmondad wrote:
> class Velocity
> {
[...]
> ref Velocity opOpAssign(string op) ( in float multiplier )
Unrelated to your question, you want to return just Velocity there.
Unlike C++, classes are reference types in D. So, Velocity itself is
essentially a Velocity* in C++.
Ali
Re: I don't get it. version(unittest) can't seem to use local variable
On 12/07/2014 5:08 p.m., dysmondad wrote:
I'm new to D. I've been using C since it was a baby and C++ back when it
was only a pre-compiler for c. So, I may just be stuck thinking in C land.
The issue is I am attempting to use the version(unittest) feature.
However the compiler pukes up the error below. I'm sure it's something
easy enough but I've not been able to find any help in Google land. I
don't know if I have the opOpAssign defined correctly or if there's
something wrong with the constructor or both.
dysmondad@Julep:~/src/D$ gdc -c velocity.d
velocity.d:110: error: no identifier for declarator v
velocity.d:110: error: semicolon expected, not '*='
velocity.d:110: error: Declaration expected, not '*='
class Velocity
{
private:
float _Y = 0.0;
float _X = 0.0;
public:
this (float x, float y )
{
_Y = y;
_X = x;
}
ref Velocity opOpAssign(string op) ( in float multiplier )
if( op == "*" )
{
_Y *= multiplier;
_X *= multiplier;
return this;
}
}
version(unittest)
{
Velocity v = new Velocity( 2.0f, 5.0f );
v *= 5.0f; // <- line 110
printf( "v = %s\n", to!string(v) );
}
try:
unittest {
Velocity v = new Velocity( 2.0f, 5.0f );
v *= 5.0f; // <- line 110
printf( "v = %s\n", to!string(v) );
}
instead. Basically version is like static if, it doesn't indicate its a
function. Instead it changes what code gets compiled.
Where as a unittest block, is essentially just a function that gets
called at a special time, that is only compiled as if version(unittest)
was also used.
I don't get it. version(unittest) can't seem to use local variable
I'm new to D. I've been using C since it was a baby and C++ back
when it was only a pre-compiler for c. So, I may just be stuck
thinking in C land.
The issue is I am attempting to use the version(unittest)
feature. However the compiler pukes up the error below. I'm sure
it's something easy enough but I've not been able to find any
help in Google land. I don't know if I have the opOpAssign
defined correctly or if there's something wrong with the
constructor or both.
dysmondad@Julep:~/src/D$ gdc -c velocity.d
velocity.d:110: error: no identifier for declarator v
velocity.d:110: error: semicolon expected, not '*='
velocity.d:110: error: Declaration expected, not '*='
class Velocity
{
private:
float _Y = 0.0;
float _X = 0.0;
public:
this (float x, float y )
{
_Y = y;
_X = x;
}
ref Velocity opOpAssign(string op) ( in float multiplier )
if( op == "*" )
{
_Y *= multiplier;
_X *= multiplier;
return this;
}
}
version(unittest)
{
Velocity v = new Velocity( 2.0f, 5.0f );
v *= 5.0f; // <- line 110
printf( "v = %s\n", to!string(v) );
}
Re: Insert a char in string
On Thursday, 10 July 2014 at 19:33:15 UTC, simendsjo wrote: On 07/10/2014 06:05 PM, Alexandre wrote: I have a string X and I need to insert a char in that string... auto X = "100"; And I need to inser a ',' in position 3 of this string..., I try to use the array.insertInPlace, but, not work... I try this: auto X = "100"; auto N = X.insertInPlace(1,'0'); Do you really want to insert a comma in the string, or do you want to format a number as "100,000,000,000.00"? For that, one approach would be as in http://dpaste.dzfl.pl/bddb71eb75bb.
Re: Question about @nogc in D 2.066
On Friday, 11 July 2014 at 21:02:30 UTC, Timon Gehr wrote:
He is allocating an immutable(int)[] here. There is no reason
why it should allocate unless providing different addresses for
different runs of the code is considered a feature, as the
literal has a compile-time known value. It's just that the
frontend does not actually elide the allocation, and this would
be a valid extension to ask for.
In any case, the allocation can be manually elided as follows:
void main(string[] args)@nogc{
auto s1 = "hello";
static immutable _a1 = [1, 2];
auto a1 = _a1;
}
(Not actually tested, because I am having trouble downloading
the beta for some reason.)
Sure, no objections here - it just happened that doing so for
string literals was more obvious because literals themselves are
immutable. And doing so for arrays requires tiny bit of
semantical analysis (probably not really difficult too, I don't
know)
Re: Question about @nogc in D 2.066
http://forum.dlang.org/thread/pxotrowaqcenrpnnw...@forum.dlang.org
Re: Question about @nogc in D 2.066
On 07/11/2014 10:39 PM, Dicebot wrote:
Key difference is that type of string literal is immutable(char)[] so it
is perfectly legal to keep it in binary text segment. Type of array
literal is just T[] (int[] here) and you can possibly mutate their
elements. Because of this each assignment of array literal needs to
allocate a new copy contrary to immutable strings which can all
reference same memory chunk.
He is allocating an immutable(int)[] here. There is no reason why it
should allocate unless providing different addresses for different runs
of the code is considered a feature, as the literal has a compile-time
known value. It's just that the frontend does not actually elide the
allocation, and this would be a valid extension to ask for.
In any case, the allocation can be manually elided as follows:
void main(string[] args)@nogc{
auto s1 = "hello";
static immutable _a1 = [1, 2];
auto a1 = _a1;
}
(Not actually tested, because I am having trouble downloading the beta
for some reason.)
Re: Question about @nogc in D 2.066
Key difference is that type of string literal is immutable(char)[] so it is perfectly legal to keep it in binary text segment. Type of array literal is just T[] (int[] here) and you can possibly mutate their elements. Because of this each assignment of array literal needs to allocate a new copy contrary to immutable strings which can all reference same memory chunk.
Re: Question about @nogc in D 2.066
On Friday, 11 July 2014 at 20:02:32 UTC, Weasel wrote: Why does the s1 not throw an error, but the a1 does? Strings don't allocate upon use whereas all other arrays do unless you specifically mark it as static - immutability isn't considered here (I think because the part of the compiler that looks at the array literal doesn't look at the type on the left hand side so it just doesn't know but i'm not sure about why). But if you make the immutable other array static it shouldn't GC allocate.
Question about @nogc in D 2.066
@nogc
void main(string[] args)
{
immutable(char)[] s1 = "hello";
immutable(int)[] a1 = [1, 2];
}
Why does the s1 not throw an error, but the a1 does? As far as I
can tell, they're both immutable arrays.
Error is: "Error: array literal @nogc function main may cause GC
allocation"
It compiles fine if I comment out the second line in main.
Re: Passing Templated Function Arguments Solely by Reference
On 07/11/2014 03:38 AM, "Nordlöw" wrote:
> https://github.com/nordlow/justd/blob/master/random_ex.d
>
> is what I have so far. Does this look ok to you?
The following seems redundant because the other isFloatingPoint!E
version uses the default arguments 0 and 1 anyway.
auto ref randInPlace(E)(ref E x) @trusted if (isFloatingPoint!E)
{
return x = uniform(cast(E)0,
cast(E)1);
}
> Question: Can I somehow avoid the duplication of logic in
>
> - auto ref randInPlace(R)(R x) @safe if (hasAssignableElements!R)
> - auto ref randInPlace(T)(ref T x) @safe if (isStaticArray!T)
The following works if you pardon the name foo. :p
auto foo(TT)(ref TT x)
{
foreach (ref e; x)
{
e.randInPlace;
}
return x;
}
/** Generate Random Contents in $(D x).
*/
auto ref randInPlace(R)(auto ref R x) @safe if (hasAssignableElements!R)
{
return foo(x);
}
/** Generate Random Contents in $(D x).
*/
auto ref randInPlace(T)(ref T x) @safe if (isStaticArray!T)
{
return foo(x);
}
Alternatively, a string mixin could be used but they should be reserved
for when there is no better solution.
Ali
Re: Value Reference Type Traits
On Friday, 11 July 2014 at 16:10:31 UTC, Nordlöw wrote: Is there a trait to check if a type is a - value type (struct, static array, etc) - reference type (class, dynamic array, string, etc) ? There's http://dlang.org/phobos/std_traits.html#hasIndirections Note that structs and static arrays may contain indirections, i.e. they are not guaranteed to have value semantics all the way down. Primitive types like int or float are definite values types.
Value Reference Type Traits
Is there a trait to check if a type is a - value type (struct, static array, etc) - reference type (class, dynamic array, string, etc) ?
Re: core.exception.InvalidMemoryOperationError
On Friday, 11 July 2014 at 11:43:44 UTC, Joakim wrote: On Thursday, 10 July 2014 at 15:36:53 UTC, francesco cattoglio wrote: A code I'm working on stops working and starts printing an infinite loop of core.exception.InvalidMemoryOperationError to the command line output. The code is quite complex and the bug seems to present itself almost in random situation so I would like to try to understand the issue better before looking for the wrong line of code hiding somewhere. I've read it might be that something is trying to allocate during a destructor call, but it sounds really strange to me that there's a neverending amount of exceptions being thrown. This is the first exception being thrown (nothing is thrown before the infinite loop begins). Anyone has suggestions/ideas/heard of a similar stuff before? If you look at the source for the garbage collector, the only place that error is called is if the gc is trying to malloc or execute other memory operations while the collector is running. I ran across this myself because an assert was getting triggered in a destructor. Since an assert tries to malloc and the destructor is called by the GC, I got an InvalidMemoryOperationError which swallowed up the message from the original assert. By putting printfs in the code path in druntime, I was able to track it down to that destructor, otherwise I had no idea where the invalid memory error was getting triggered. You can probably do the same, but you can be sure it's a GC issue, and I would guess tied to allocating in a destructor (unless you happen to be calling InvalidMemoryOperationErrors somewhere in your own code or some library that you're using, which is unlikely). It's unfortunate that you wrote this only 4 hours ago, because I already spent the morning doing more-or-less the same thing, and finaly realized what was happening and WHO was allocating during a destructor. :o) It's even somewhat told in the docs of core.exception module. What I really don't understand is how the hell was it possible that something managed to either recurse or loop to generate an infinite WOE (Wall Of Exceptions).
DMDScript
Tried to compile on linux, got this error message (I guess I can
fix it):
dmd -c textgen.d
textgen.d(36): Error: cannot implicitly convert expression
("DMDScript fatal runtime error: ") of type string to char[]
textgen.d(36): Error: cannot implicitly convert expression (0) of
type int to char[]
textgen.d(36): Error: cannot implicitly convert expression
("ERR_RUNTIME_PREFIX") of type string to char[]
textgen.d(37): Error: cannot implicitly convert expression ("No
default value for COM object") of type string to char[]
textgen.d(37): Error: cannot implicitly convert expression (0) of
type int to char[]
textgen.d(37): Error: cannot implicitly convert expression
("ERR_COM_NO_DEFAULT_VALUE") of type string to char[]
textgen.d(38): Error: cannot implicitly convert expression ("%s
does not have a [[Construct]] property") of type string to char[]
textgen.d(38): Error: cannot implicitly convert expression (0) of
type int to char[]
textgen.d(38): Error: cannot implicitly convert expression
("ERR_COM_NO_CONSTRUCT_PROPERTY") of type string to char[]
textgen.d(39): Error: cannot implicitly convert expression
("argument type mismatch for %s") of type string to char[]
textgen.d(39): Error: cannot implicitly convert expression (0) of
type int to char[]
textgen.d(39): Error: cannot implicitly convert expression
("ERR_DISP_E_TYPEMISMATCH") of type string to char[]
textgen.d(40): Error: cannot implicitly convert expression
("wrong number of arguments for %s") of type string to char[]
textgen.d(40): Error: cannot implicitly convert expression (0) of
type int to char[]
textgen.d(40): Error: cannot implicitly convert expression
("ERR_DISP_E_BADPARAMCOUNT") of type string to char[]
textgen.d(41): Error: cannot implicitly convert expression ("%s
Invoke() fails with COM error %x") of type string to char[]
textgen.d(41): Error: cannot implicitly convert expression (0) of
type int to char[]
textgen.d(41): Error: cannot implicitly convert expression
("ERR_COM_FUNCTION_ERROR") of type string to char[]
textgen.d(42): Error: cannot implicitly convert expression
("Dcomobject: %s.%s fails with COM error %x") of type string to
char[]
textgen.d(42): Error: cannot implicitly convert expression (0) of
type int to char[]
textgen.d(42): Error: cannot implicitly convert expression
("ERR_COM_OBJECT_ERROR") of type string to char[]
linux.mak:178: recipe for target 'textgen.o' failed
make: *** [textgen.o] Error 1
Re: get number of items in DList
On Fri, Jul 11, 2014 at 10:23:58AM -0300, Ary Borenszweig via Digitalmars-d-learn wrote: > On 7/11/14, 4:46 AM, bearophile wrote: > >pgtkda: > > > >>How can i get the number of items which are currently hold in a > >>DList? > > > >Try (walkLength is from std.range): > > > >mydList[].walkLength > > > >Bye, > >bearophile > > So the doubly linked list doesn't know it's length? That seems a bit > inefficient... It should be relatively simple to write a wrapper that *does* keep track of length. The main problem, though, comes from list splicing: given two arbitrary points in the list, if you splice out the section of the list in between, there's no easy way to know how many items lie in between, so you'll have to walk the list to recompute the length then. Which sorta defeats the purpose of having a linked list. :) T -- Valentine's Day: an occasion for florists to reach into the wallets of nominal lovers in dire need of being reminded to profess their hypothetical love for their long-forgotten.
Re: get number of items in DList
Ary Borenszweig: So the doubly linked list doesn't know it's length? That seems a bit inefficient... Have you tried to compile mydList.length or mydList[].length? If both don't compile, then you have to walk the items. Walking the items is not efficient, but: - Linked lists are very uncommonly needed. In 98-99% of cases an array of items or an array of pointers is better (faster for all operations, more efficient for memory used, leading to smaller binary, more compatible with other APIs, and so on). - Most functional algorithms that work on lists do not need to know the length of the list. Bye, bearophile
Re: get number of items in DList
On 7/11/14, 4:46 AM, bearophile wrote: pgtkda: How can i get the number of items which are currently hold in a DList? Try (walkLength is from std.range): mydList[].walkLength Bye, bearophile So the doubly linked list doesn't know it's length? That seems a bit inefficient...
Re: core.exception.InvalidMemoryOperationError
On Thursday, 10 July 2014 at 15:36:53 UTC, francesco cattoglio wrote: A code I'm working on stops working and starts printing an infinite loop of core.exception.InvalidMemoryOperationError to the command line output. The code is quite complex and the bug seems to present itself almost in random situation so I would like to try to understand the issue better before looking for the wrong line of code hiding somewhere. I've read it might be that something is trying to allocate during a destructor call, but it sounds really strange to me that there's a neverending amount of exceptions being thrown. This is the first exception being thrown (nothing is thrown before the infinite loop begins). Anyone has suggestions/ideas/heard of a similar stuff before? If you look at the source for the garbage collector, the only place that error is called is if the gc is trying to malloc or execute other memory operations while the collector is running. I ran across this myself because an assert was getting triggered in a destructor. Since an assert tries to malloc and the destructor is called by the GC, I got an InvalidMemoryOperationError which swallowed up the message from the original assert. By putting printfs in the code path in druntime, I was able to track it down to that destructor, otherwise I had no idea where the invalid memory error was getting triggered. You can probably do the same, but you can be sure it's a GC issue, and I would guess tied to allocating in a destructor (unless you happen to be calling InvalidMemoryOperationErrors somewhere in your own code or some library that you're using, which is unlikely).
Re: Passing Templated Function Arguments Solely by Reference
On Wednesday, 9 July 2014 at 07:43:57 UTC, Ali Çehreli wrote: Ali This https://github.com/nordlow/justd/blob/master/random_ex.d is what I have so far. Does this look ok to you? Question: Can I somehow avoid the duplication of logic in - auto ref randInPlace(R)(R x) @safe if (hasAssignableElements!R) - auto ref randInPlace(T)(ref T x) @safe if (isStaticArray!T) ?
Re: How to interact with fortran code
On Thursday, 10 July 2014 at 12:12:20 UTC, Marc Schütz wrote: On Wednesday, 9 July 2014 at 15:09:08 UTC, Chris wrote: On Wednesday, 9 July 2014 at 15:00:25 UTC, seany wrote: I apologize many times for this question, may be this had already been answered somewhere, but considering today the last of my nerve is broken, I can not really find the soution. So I have a D code, which acts as a central manager of all my codes, reads user input, reads files, etc, and based on the file readouts, I would like to pass some variables from the D code to a fortran code, in binary format, perhaps, if such a thing exists, instead of encoding to text/ ASCII first. I would also like to read some (not all) variables back from the fortran code. The Fortran code resides in a subdirectory to the path/to/d/code How to do this? is there a preffered way / easier than system call way to interface D and Fortran code? This must be Fortan code - these are the standard atmospheric chemistry codes. I apologize again if the question is stupid, trust me, today all my nerves are broken. Off the top of my head I'd say you could try to interface Fortran and C. Then you could interface D and C, i.e. D > C > Fortran. http://fortranwiki.org/fortran/show/Generating+C+Interfaces https://gcc.gnu.org/onlinedocs/gcc-3.4.4/g77/C-Interfacing-Tools.html To expand on that: You don't actually need to write a C glue layer between D and Fortran. All you need to do is make your Fortran functions accessible for C code. As I'm not familiar with Fortran, I don't know how exactly that works, but it could involve telling the compiler to use the right calling convention, and use the right name mangling. If you are able to use Fortran 2003 or later, Fortran's iso_c_binding makes it simple to expose Fortran functions to be called from C and vice versa. I don't know of any good online references, but a lot of good examples can be found in the source for the Fortran interface to the GSL: http://www.lrz.de/services/software/mathematik/gsl/fortran/index.html An example of compiling and linking: http://compgroups.net/comp.lang.fortran/usage-of-iso_c_binding/155309 If iso_c_binding is not available, then it's not as pretty: http://www.yolinux.com/TUTORIALS/LinuxTutorialMixingFortranAndC.html
Re: Passing Templated Function Arguments Solely by Reference
On Wednesday, 9 July 2014 at 07:43:57 UTC, Ali Çehreli wrote: Phobos algorithms use ranges. The following is what I've come up with very quickly: Thx
Re: get number of items in DList
pgtkda: How can i get the number of items which are currently hold in a DList? Try (walkLength is from std.range): mydList[].walkLength Bye, bearophile
get number of items in DList
How can i get the number of items which are currently hold in a DList?
