Re: cannot access frame of function
On Monday, 18 September 2017 at 21:58:39 UTC, Alex wrote:
On Monday, 18 September 2017 at 18:49:54 UTC, ag0aep6g wrote:
Doesn't work for me. This still fails compilation with the
same error:
import std.algorithm.iteration : sum, cumulativeFold;
void main()
{
double[5] a;
auto asum = 1.23;
auto jProbs = a[].cumulativeFold!((a, b) => (a + b)/asum);
}
So, this is a bug, isn't it? I assume, I should file it then...
I have this same issue. Anyone have any thoughts on a workaround?
For example, my attempt at an exponential moving average doesn't
compile:
auto ema(Range,T) (Range rng, int period, T seed) {
return rng.cumulativeFold!((a,b) =>
a+(2.0/(period+1))*(b-a))(seed.to!double);
}
So I ended up with this:
auto ema(Range,T) (Range rng, int period, T seed) {
struct EMA(Range) {
double currentValue;
double weighting;
Range rng;
this (Range r, int p, double s) {
currentValue = s;
weighting = 2.0 / (p+1);
rng = r;
}
auto front() { return currentValue; }
auto popFront() {
rng.popFront;
if (!rng.empty){
currentValue += (rng.front -
currentValue)*weighting;
}
}
auto empty() { return rng.empty; }
}
return EMA!Range(rng,period,seed.to!double);
}
Thanks,
Jordan
remote execute program
I am wanting to write a short program (on a ‘server’ you could say) that takes a command, runs it (as on the command line, so an executable with arguments or a shell command) and returns a 3-tuple with an int for the return code, plus the textual outputs that it generates to stdout and stderr. I can see a number of suitable routines in the D runtime libraries, which are already D-ified to save me a some trouble mindlessly converting code from C. Where I could do with some help is as follows: I'm needing to send the commands to a remote box using http has to be used because the local-end program (on an iPad) that I have to interfacing to can only speak http/https, and can not handle just a straight eg TCP connection. Despite the overheads from using http, if I can employ gzip compression on the link then that will be a big gain. Could anyone give me some general pointers for where to look? The server box is a linux machine. I'm a very experienced professional C programmer but amazingly have never done anything with *nix in general or http-related C libraries. I asked a question in this forum earlier about general low-level networking, but now this requirement has come up that mandates the use of very simple http and needs only synchronous operations. The impressive framework that is vibe.d has already been mentioned, but the amount of reading matter is rather daunting. A simple D example of an http transaction would be very helpful.
Re: Building Derelict based application under windows
On Thursday, 22 March 2018 at 20:51:36 UTC, ANtlord wrote: Thanks in advance. Please feel free to ask any question Your errors with the derelict libs are linker errors, with the early ones being this one: "warning LNK4003: invalid library format; library ignored" At the top of the output, DUB is warning you that you've put -m64 in the package file and shouldn't do that. I would guess that's your problem. The libraries are being compiled as 32-bit OMF, which is default on the prepackaged DMD binaries on Windows, but the -m64 in your dflags is causing your app to compile as 64-bit. Try taking -m64 out of your package file and put -ax86_64 on your DUB command line instead.
Re: #import mapi.h
On Thursday, 22 March 2018 at 21:45:40 UTC, Martin Tschierschke
wrote:
On Thursday, 22 March 2018 at 17:42:46 UTC, Paul Backus wrote:
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin
Tschierschke wrote:
Is there an step by step introduction how to convert a C
header of an external lib into the right extern(C){} block?
In addition to what others have said, I found the following
article on the D Wiki useful:
https://wiki.dlang.org/D_binding_for_C
Thank you, this one is very good!
If you have Learning D, chapter 9 is all about interface D with C.
Re: #import mapi.h
On Thursday, 22 March 2018 at 17:42:46 UTC, Paul Backus wrote:
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin
Tschierschke wrote:
Is there an step by step introduction how to convert a C
header of an external lib into the right extern(C){} block?
In addition to what others have said, I found the following
article on the D Wiki useful:
https://wiki.dlang.org/D_binding_for_C
Thank you, this one is very good!
Building Derelict based application under windows
Hello! First of all I don't know what my problem is but please don't close the thread and give me a chance. I have been working on DMD under Linux since I met D. Short time ago I got a reason to make an application for Windows. I took DerelictAL[1], DerelictOgg[2] and DerelictVorbis[3] implementing basic prototype under Linux. So everything ok under Linux. Unfortunately I get a couple of issue under Windows 7. The Windows is launched under VirtualBox. The first one is target architecture the application is compiled for. I installed DMD 2.079 and Visual Studio 2015.2 so I corrected sc.ini consider the article[4] from the wiki. The file has the content that is available by the link [5]. But I'm not sure that dmd compiles code for 64 bit architecture because an address of any pointer consists of 6 symbols instead of 16. A pointer in C++ application consists of 16 symbols. There is D code [6]. The second one is warnings and errors during compilation of my application. Typical messages shows up inability of linker to recognize any direlict library so there are a couple of errors about unresolved symbols of direlict libraries. Full list of errors and warnings is available by the link [7]. Please help me to figure out how I can fix the issue. I don't want use another language to create the application. My environment Windows 7 64bit (under VirtualBox) DMD 2.079 Visual Studio 2015.2 [1] https://github.com/DerelictOrg/DerelictAL [2] https://github.com/DerelictOrg/DerelictVorbis [3] https://github.com/DerelictOrg/DerelictOgg [4] https://wiki.dlang.org/Installing_DMD [5] https://gist.github.com/ANtlord/0c78180f627eb544cc69770ecbe997a7 [6] https://gist.github.com/ANtlord/e0a7e183498095b2f8a8726f35e63803 [7] https://gist.github.com/ANtlord/e8a0cc6f20b2b46124ae3cd72ed04bed Thanks in advance. Please feel free to ask any question
Re: Help debugging an core.exception.OutOfMemoryError
On 03/22/2018 02:45 AM, Danny Arends wrote: Hey all, When running a D program that i wrote (32bit mode, windows10), an OutOfMemory exception being thrown when executing the program: core.exception.OutOfMemoryError@src\core\exception.d(702): Memory allocation failed However there is no stack trace being generated (due to the program being out of memory). How do I figure out where in the user code the out of memory error is coming from/occurring ? Thanks in advance, Danny ps. Using Linux 64bit, this error does not occur I don't think you can point at any one place because it's probably really running out of memory. The fact that it's only in 32-bit suggests that you're allocating large amounts of memory (perhaps simply some arrays are getting larger) and that some values in unrelated parts of the code are mistaken to be pointers into that memory, making them "alive" in the eye of the GC. This is a common issue with imprecise GCs like the current one that D uses. (It's highly likely that D's GC will always be imprecise because D allows casting a pointer to an integral type. For that reason, the GC cannot be sure whether your integer value 0x12345678 is a pointer or not.) If that really is the reason, a common advice is moving to 64-bit, where the likelihood of false pointers is about 4 billion times less than happening in 32-bit. (If my math is correct. :) ) Ali
Re: Checking if a flag was passed to the compiler
On Thursday, 22 March 2018 at 14:58:56 UTC, Seb wrote:
For reference and completeness, a simple example:
```d
void main()
{
enum isDIP1000 = __traits(compiles, () @safe {
int x;
int* p;
p =
});
pragma(msg, isDIP1000);
}
```
normal: https://run.dlang.io/is/RID7vh
-dip1000: https://run.dlang.io/is/1yJfVQ
(this could of course be fancier)
Thanks
Re: Is it possible to exit a contract?
On Thursday, 22 March 2018 at 16:22:04 UTC, Ali Çehreli wrote: Never thought of it before. :) I would put all that code into a function and call from the out block. I rejected this, because I've got an unease feeling using extra functions in contract programming. Can't tell, where this feeling comes from; maybe just because I've too few experience with contract programming...
Re: #import mapi.h
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin Tschierschke
wrote:
Is there an step by step introduction how to convert a C header
of an external lib into the right extern(C){} block?
In addition to what others have said, I found the following
article on the D Wiki useful:
https://wiki.dlang.org/D_binding_for_C
Re: Is it possible to exit a contract?
On Thursday, 22 March 2018 at 13:16:00 UTC, berni wrote:
Part of my code looks like this:
out (result)
{
if (result==true)
{
lots of assertions...
}
}
I would prefer an early exit like:
out (result)
{
if (result==false) return;
lots of assertions...
}
Is this possible somehow (return and break don't do the
job...). The only thing I found is using goto, which I prefer
over that gigantic if-block, but maybe there is something
better, I don't know of?
It's a hack, but it works:
void bar()
in {(){
return;
assert(false);
}();}
body
{
}
unittest {
bar();
}
--
Simen
Re: Is it possible to exit a contract?
On 03/22/2018 06:16 AM, berni wrote:
Part of my code looks like this:
out (result)
{
if (result==true)
{
lots of assertions...
}
}
I would prefer an early exit like:
out (result)
{
if (result==false) return;
lots of assertions...
}
Is this possible somehow (return and break don't do the job...). The
only thing I found is using goto, which I prefer over that gigantic
if-block, but maybe there is something better, I don't know of?
Never thought of it before. :) I would put all that code into a function
and call from the out block.
Ali
Re: OK, I'm stumped on this one: dstep, struct, mixin, bitfields
On Thursday, 22 March 2018 at 09:55:44 UTC, Russel Winder wrote: I am guessing you mean against DStep rather than D :-) Yes :) Though clearly T and I would prefer version not to be a D keyword. I suspect I have seen one place where DStep has turned version into version_ where version was a variable name. In this case "version" was a string used to create a bitfield using a mixin(bitfield!(…)) construct. Is that likely easy to fix? Yes. It's not a string literal in the C code. The identifier should be renamed before it's added to the call to "bitfield". -- /Jacob Carlborg
Re: why does this compile fine, but dies when you run it.
On Thursday, 22 March 2018 at 14:05:02 UTC, steven kladitis wrote:
-- what is the difference between int[] x; and int[int] x;
int[] x; is like
struct _Int_Array
{
size_t len;
int* ptr;
}
_Int_Array y;
int i = 5;
x[i] = i; // this and the line below crash or assert, due to a
null pointer
*(y.ptr +i) = 5;
are both the same;
int[int] is a completely different beast. is it a hashtable that
maps ints to int.
its a lot closer to int[string] than it is to int[]
see https://dlang.org/spec/arrays.html vs
https://dlang.org/spec/hash-map.html
Re: Checking if a flag was passed to the compiler
On Thursday, 22 March 2018 at 12:02:40 UTC, Nicholas Wilson wrote:
On Thursday, 22 March 2018 at 10:08:31 UTC, Nordlöw wrote:
Is there a way to check in code whether a specific flag,
-dip1000 in my case, was passed to the compiler?
Most command line arguments that are detectable set a version,
e.g. D_Coverage, unittest, assert,D_BetterC. I don't see
dip1000 in LDC's list of version statements.
You could do a !__traits(compiles, { something forbidden by
dip1000} );
For reference and completeness, a simple example:
```d
void main()
{
enum isDIP1000 = __traits(compiles, () @safe {
int x;
int* p;
p =
});
pragma(msg, isDIP1000);
}
```
normal: https://run.dlang.io/is/RID7vh
-dip1000: https://run.dlang.io/is/1yJfVQ
(this could of course be fancier)
Re: #import mapi.h
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin Tschierschke
wrote:
Is there an step by step introduction how to convert a C header
of an external lib into the right extern(C){} block?
In short, they should be binary compatible: where is a pointer on
C side, should be a pointer on D side, same for integer sizes,
data layout an calling conventions.
Re: #import mapi.h
On Thursday, 22 March 2018 at 12:53:23 UTC, Martin Tschierschke
wrote:
On Wednesday, 21 March 2018 at 17:12:07 UTC, Timoses wrote:
[...]
I got it, my first mini test with C bindings!
Important missing at first: (stderr)
import core.stdc.stdio : stderr, FILE;
and use of toStringz inside: mapi_query(dbh, toStringz(q) )
After installing monetdb and starting the server with:
https://www.monetdb.org/Documentation/UserGuide/Tutorial
My minimal version of the example compiled with
dmd app.d -I /usr/local/lib/libmapi.so
(My dub.json is still incomplete so the linking failed.)
Here is the code: (only the minimum of mapi.h is icluded!)
```
std.stdio;
import std.string;
/* interfacing winth monetdb #include mapi.h */
/* minimum to run code of example at:
https://www.monetdb.org/Documentation/Manuals/SQLreference/Programming/MAPI */
import core.stdc.stdio : stderr,FILE;
import core.stdc.stdlib;
struct MapiStruct;
alias Mapi = MapiStruct*;
struct MapiStatement;
alias MapiHdl = MapiStatement*;
enum MOK = 0 ;
alias MapiMsg = int;
extern(System){
Mapi mapi_connect(const char* host, int port, const char*
username, const char* password, const char* lang, const char*
dbname);
MapiHdl mapi_query(Mapi mid, const char *cmd);
int mapi_fetch_row(MapiHdl hdl);
char *mapi_fetch_field(MapiHdl hdl, int fnr);
MapiMsg mapi_error(Mapi mid);
MapiMsg mapi_explain(Mapi mid, FILE* fd);
MapiMsg mapi_destroy(Mapi mid);
MapiMsg mapi_close_handle(MapiHdl hdl);
MapiMsg mapi_explain_result(MapiHdl hdl, FILE* fd);
MapiMsg mapi_next_result(MapiHdl hdl);
MapiMsg mapi_explain_query(MapiHdl hdl, FILE* fd);
char *mapi_result_error(MapiHdl hdl);
}
void die(Mapi dbh, MapiHdl hdl) {
if (hdl != null) {
mapi_explain_query(hdl, stderr);
do {
if (mapi_result_error(hdl) != null)
mapi_explain_result(hdl, stderr);
} while (mapi_next_result(hdl) == 1);
mapi_close_handle(hdl);
mapi_destroy(dbh);
} else if (dbh != null) {
mapi_explain(dbh, stderr);
mapi_destroy(dbh);
} else {
fprintf(stderr, "command failed\n");
}
exit(-1);
}
MapiHdl query(Mapi dbh, string q) {
MapiHdl ret = null;
if ((ret = mapi_query(dbh, toStringz(q) )) == null ||
mapi_error(dbh) != MOK)
die(dbh, ret);
return(ret);
}
void update(Mapi dbh, string q) {
MapiHdl ret = query(dbh, q);
if (mapi_close_handle(ret) != MOK)
die(dbh, ret);
}
void main()
{
auto dbh = mapi_connect("localhost", 5, "monetdb",
"monetdb", "sql", "voc");
writeln("DB-connect");
update(dbh, "CREATE TABLE emp (name VARCHAR(20), age INT)");
writeln("create");
update(dbh, "INSERT INTO emp VALUES ('John', 23)");
update(dbh, "INSERT INTO emp VALUES ('Mary', 22)");
auto hdl = query(dbh, "SELECT * FROM emp");
while (mapi_fetch_row(hdl)) {
auto name = mapi_fetch_field(hdl, 0);
auto age = mapi_fetch_field(hdl, 1);
printf("%s is %s\n", name, age);
}
}
```
Will try to make a complete binding available later...
Re: why does this compile fine, but dies when you run it.
On Wednesday, 21 March 2018 at 18:55:34 UTC, Adam D. Ruppe wrote:
On Wednesday, 21 March 2018 at 18:53:39 UTC, steven kladitis
wrote:
int[] array3;
array3[0]=4;
array3 is empty. You are trying to set a value that doesn't
exist..
import std.stdio;
void main(){
int[3] array1 = [ 10, 20, 30 ];
auto array2 = array1; // array2's elements are different
// from array1's
array2[0] = 11;
int[] array3;
//array4[0]=3;
array3 ~=4;
auto array4 = array3;
array4 ~=2;
int[string] a1;
int[int] a2;
a1["V"]=2;
a2[4]=3;
writeln(array1,'\n',array2,'\n',array3,'\n',array4,'\n',a1,'\n',a2);
}
-- this works, why??
-- what is the difference between int[] x; and int[int] x;
-- thanks
-- Steven
Re: Static Arrays: Behaviour of Passing & Returning
On Wednesday, 21 March 2018 at 12:15:13 UTC, Simen Kjærås wrote: I'm pretty sure you're seeing NRVO - Named Return Value Optimization. Also called copy elision: https://en.wikipedia.org/wiki/Copy_elision The compiler sees that when you return r, it's immediately assigned to b. Since it's a waste of cycles to allocate twice and copy the values, the function is told where the result will end up, and writes it there immediately. The reason you don't see that with c is that the compiler isn't very smart, especially not with optimizations turned off, so it doesn't know for sure that it can safely overwrite the values already in c at that point. Thanks a lot, that explains things. I was really surprised, as I had compiler optimizations in mind before I posted. I ran the tests without any optimization using ldc2 -g -O0, but the outcome was the same. Thanks for your help, qnerd
Is it possible to exit a contract?
Part of my code looks like this:
out (result)
{
if (result==true)
{
lots of assertions...
}
}
I would prefer an early exit like:
out (result)
{
if (result==false) return;
lots of assertions...
}
Is this possible somehow (return and break don't do the job...).
The only thing I found is using goto, which I prefer over that
gigantic if-block, but maybe there is something better, I don't
know of?
Re: #import mapi.h
On Wednesday, 21 March 2018 at 17:12:07 UTC, Timoses wrote:
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin
Tschierschke wrote:
Is there an step by step introduction how to convert a C
header of an external lib into the right extern(C){} block?
A blog post or tutorial, or chapter in a D book? (I have those
from Packt Publishing)
While googling I found this:
https://dlang.org/blog/2017/12/05/interfacing-d-with-c-getting-started/
Haven't read it yet, but might give you some more insight.
For automatic conversion I stumbled across Dstep which I so far
like a lot:
https://github.com/jacob-carlborg/dstep
Thank you! I will have a look at both, an Mike Parker is pointing
to his book, too,
so now together with the post from "nkm1" I should be able to
make it!
@ketmar, I learned C but the counter of years from that time was
stored in a nibble and so I got an overflow...error :-)
Re: #import mapi.h
On Wednesday, 21 March 2018 at 18:42:43 UTC, nkm1 wrote: On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin Tschierschke wrote: [...] The easiest thing to do is to write a wrapper in C. The wrapper will include all necessary headers and provide some easy to use functions that you can call from D. Of course, you'll need to use a C compiler to compile it. Anyway, this header looks very straightforwar, no particular tricks with the preprocessor. It should be something like this (untested, obviously): [...] Thank you! Especially this was a missing link: struct MapiStruct; alias Mapi = MapiStruct*;
Re: Checking if a flag was passed to the compiler
On Thursday, 22 March 2018 at 10:08:31 UTC, Nordlöw wrote:
Is there a way to check in code whether a specific flag,
-dip1000 in my case, was passed to the compiler?
Most command line arguments that are detectable set a version,
e.g. D_Coverage, unittest, assert,D_BetterC. I don't see dip1000
in LDC's list of version statements.
You could do a !__traits(compiles, { something forbidden by
dip1000} );
Re: Is there a way to pipeline program with random-access ranges in C#?
On Thursday, 22 March 2018 at 09:59:28 UTC, Kagamin wrote: On Thursday, 22 March 2018 at 09:04:12 UTC, Dukc wrote: So the real difference is that random-accesss ranges are not input-ranges in C# (or Rust, judging by a quick look I recently took) but can be used to fetch one. A bit cumbersome perhaps, but logical. I think I understand it now. Thank you. IList inherits from IEnumerable, which is an input range. Oops. Well, all the better!
Re: Issue with traits usability
On Wednesday, 21 March 2018 at 15:36:01 UTC, Márcio Martins wrote:
Hi!
How do I get past this?
static struct X {
int x;
private enum T = 1;
private alias M = string;
}
foreach (Member; __traits(allMembers, X)) {
pragma(msg, __traits(getProtection, __traits(getMember, X,
Member)));
}
Output:
public
private
c.d(1084): Error: argument string has no protection
c.d(1084):while evaluating pragma(msg,
__traits(getProtection, string))
What I want to achieve essentially is skip all X's aliases and
templates, but get everything else, like enums and data
members. How would I go about this in a robust way?
I actually want to skip aliases, and templates.
__traits(compiles) is your friend:
unittest {
static struct X {
int x;
private enum T = 1;
private alias M = string;
}
foreach (Member; __traits(allMembers, X)) {
static if (__traits(compiles, __traits(getProtection,
__traits(getMember, X, Member {
pragma(msg, __traits(getProtection,
__traits(getMember, X, Member)));
}
}
}
--
Simen
Re: OK, I'm stumped on this one: dstep, struct, mixin, bitfields
On Wednesday, 21 March 2018 at 19:41:39 UTC, H. S. Teoh wrote:
version(all) { ... }
version(none) { ... }
version(Posix) { ... }
version(Windows) { ... }
But yeah, using "version" for this purpose makes the very
common identifier "version" unavailable for use. I've been
bitten by this multiple times.
auto version = getVersion();// NG
auto ver = getVersion();// OK
struct PacketHeader {
ushort version; // NG
ushort ver; // OK
}
C code also uses `in`, `out` and `with` as identifiers.
I think, with some funny escape sequences we can do without any
keyword at all:
\1(all) { ... }
\1(none) { ... }
\1(Posix) { ... }
\1(Windows) { ... }
\5 version = getVersion();
\2 PacketHeader {
\6 version;
}
Checking if a flag was passed to the compiler
Is there a way to check in code whether a specific flag, -dip1000 in my case, was passed to the compiler?
Re: Is there a way to pipeline program with random-access ranges in C#?
On Thursday, 22 March 2018 at 09:04:12 UTC, Dukc wrote: So the real difference is that random-accesss ranges are not input-ranges in C# (or Rust, judging by a quick look I recently took) but can be used to fetch one. A bit cumbersome perhaps, but logical. I think I understand it now. Thank you. IList inherits from IEnumerable, which is an input range.
Re: OK, I'm stumped on this one: dstep, struct, mixin, bitfields
On Wed, 2018-03-21 at 22:18 +0100, Jacob Carlborg via Digitalmars-d-learn wrote: > On 2018-03-21 20:30, Russel Winder wrote: > > > Thanks to Adam and Ali, it was clear and obvious. > > Please report and issue so it's not forgotten. I am guessing you mean against DStep rather than D :-) Though clearly T and I would prefer version not to be a D keyword. I suspect I have seen one place where DStep has turned version into version_ where version was a variable name. In this case "version" was a string used to create a bitfield using a mixin(bitfield!(…)) construct. Is that likely easy to fix? -- Russel. == Dr Russel Winder t: +44 20 7585 2200 41 Buckmaster Roadm: +44 7770 465 077 London SW11 1EN, UK w: www.russel.org.uk signature.asc Description: This is a digitally signed message part
Help debugging an core.exception.OutOfMemoryError
Hey all, When running a D program that i wrote (32bit mode, windows10), an OutOfMemory exception being thrown when executing the program: core.exception.OutOfMemoryError@src\core\exception.d(702): Memory allocation failed However there is no stack trace being generated (due to the program being out of memory). How do I figure out where in the user code the out of memory error is coming from/occurring ? Thanks in advance, Danny ps. Using Linux 64bit, this error does not occur
Re: Is there a way to pipeline program with random-access ranges in C#?
On Wednesday, 21 March 2018 at 08:40:25 UTC, Kagamin wrote: On Wednesday, 21 March 2018 at 07:40:01 UTC, Dukc wrote: ...except that IEnumerables cannot popBack(), so can only do that by doing an additional copy and reversing that. But I quess there's no better alternative, short of doing it C-style... A random access range would be represented as IList, backward iteration can be just a part of chunking. So the real difference is that random-accesss ranges are not input-ranges in C# (or Rust, judging by a quick look I recently took) but can be used to fetch one. A bit cumbersome perhaps, but logical. I think I understand it now. Thank you.
Re: Understanding slide
On Thursday, 22 March 2018 at 03:58:35 UTC, Seb wrote: On Thursday, 22 March 2018 at 03:39:38 UTC, Jordan Wilson wrote: auto a = iota(5).slide!(Yes.withPartial)(3); auto b = iota(5).slide!(No.withPartial)(3); assert (a.equal(b)); The assert passes, but I would expect it to fail? They both are: [[0,1,2],[1,2,3],[2,3,4]] Thanks, Jordan See: https://forum.dlang.org/post/asocdlqaihkskiilr...@forum.dlang.org Ah I see. Apologies, I normally read the forums every day, must have just missed this one. Thanks
Re: Manipulate slice or specific element of range and return range
On Thursday, 22 March 2018 at 04:49:39 UTC, Seb wrote: No need for regular expressions. D is powerful enough without them: ``` alias lowercased = (m, n) => m.take(n).asLowerCase.chain(m.drop(n)); ``` https://run.dlang.io/is/cSL0si And with the filter, so it passes the assert: ``` string input = "My Capital String"; auto lower1 = input.take(1).asLowerCase.chain(input.drop(1).filter!(c => c != ' ')).array; assert(lower1 == "myCapitalString"); ``` Also a few more options (including a slice version): https://run.dlang.io/is/dZHcSo As the input is never read until the array() is run, each element in the array should only be copied from RAM to the stack once. And if you compile with LDC a lot of it can be inlined and the stack copies of the range structs and elements should be minimised even further.
Re: recursive template expansion: Why does this not compile?
On Wednesday, 21 March 2018 at 23:05:22 UTC, Jonathan M Davis wrote: On Wednesday, March 21, 2018 22:50:32 Ontonator via Digitalmars-d-learn wrote: On Wednesday, 21 March 2018 at 06:39:22 UTC, ag0aep6g wrote: > On 03/21/2018 01:47 AM, Ontonator wrote: >> The following code does not compile: >>> [...] >> >> It gives the error: >>> [...] >> >> The aliases do not have to be aliases, as long as there is >> some reference to the class (e.g. method and variable >> declarations also work). What exactly is the reason for >> this error? > > Compiler bug. It works when you move the declaration of `B` > before the one of `A`. Order shouldn't matter there. Is this a known bug, or should I report it? If you can't find it searching on bugzilla, report it. - Jonathan M Davis https://issues.dlang.org/show_bug.cgi?id=18646
Re: Calling Windows Command
On Wednesday, 21 March 2018 at 18:50:38 UTC, Vino wrote:
Hi All,
Request your help in calling the windows command to delete all
file and folders recursively as the D function rmdirRecurse
does not delete file in the permission of the file is readonly
in windows 2008 R2
import std.process: execute;
import std.array: empty;
auto RemoveDir () (
auto dFiles = "C:\\Temp\Test1";
auto Step = "run";
if (Step == "run" && !dFiles.empty) {
version(Windows)
{
foreach(d; dFiles) {
execute(["rmdir.exe","-command", "/S /Q", `~d~`]); } } }
return dFiles;
)
void main () {
writeln(RemoveDir);
}
From,
Vino.N
It is faster if you use SHFileOperationW directly on Windows (and
also it will ignore readonly attributes):
https://msdn.microsoft.com/en-us/library/windows/desktop/bb762164(v=vs.85).aspx
//not tested
void winrmdir(string path)
{
import core.sys.windows.shellapi;
import std.exception : enforce;
import std.file: FileException;
import std.utf: toUTF16;
auto shpath = (path ~ "\0\0").toUTF16();
SHFILEOPSTRUCTW s;
s.wFunc = FO_DELETE;
s.pFrom = shpath.ptr;
s.fFlags = FOF_NOCONFIRMATION | FOF_SILENT | FOF_NOERRORUI;
enforce!FileException(SHFileOperationW() == 0 &&
!s.fAnyOperationsAborted);
}
