Re: Phobos in BetterC
On Saturday, 9 March 2019 at 19:40:27 UTC, Sebastiaan Koppe wrote: On Saturday, 9 March 2019 at 17:14:37 UTC, 9il wrote: It was fixed to be used in BetterC. If it still does not work you can open an issue and ping me (@9il). That is awesome. I suppose support for betterC is only from v3 upwards? Yes. However, it is hard to test. Also, BetterC works better in LDC. I have never seen a real production betterC program compiled with DMD.
Re: this is null
On Saturday, 9 March 2019 at 21:00:51 UTC, Ali Çehreli wrote: I haven't run the code but which pointer is null? Try adding I mean `this` by "this" word. You can see that `this` is null if you run gdb and before that line make `p/x this` [0] this check as well: auto node = this.list.getFisrtFreeOrAdd(memViewLen); assert(node !is null); I get segfault in `getFisrtFreeOrAdd` method. Before the line I have an assertion [1]. It looks like the program misses (I have no idea how) `list` object while calling its method `getFisrtFreeOrAdd`. [0] https://github.com/ANtlord/deadmemory/blob/master/src/deadmemory/freelist.d#L56 [1] https://github.com/ANtlord/deadmemory/blob/master/src/deadmemory/mem.d#L19
Re: this is null
On 03/09/2019 12:10 PM, ANtlord wrote: On Saturday, 9 March 2019 at 20:04:53 UTC, Paul Backus wrote: You can end up with a null `this` reference if you dereference a null pointer to a struct and then call a method on the result. For example: I can but my reference is not null before calling. Take a look at the line of code [0]. There is a check before the line. https://github.com/ANtlord/deadmemory/blob/master/src/deadmemory/mem.d#L20 [0] I haven't run the code but which pointer is null? Try adding this check as well: auto node = this.list.getFisrtFreeOrAdd(memViewLen); assert(node !is null); Ali
Re: this is null
On Saturday, 9 March 2019 at 20:04:53 UTC, Paul Backus wrote:
struct S
{
bool isThisNull() { return is null; }
}
void main()
{
import.std.stdio;
S* p = null;
writeln((*p).isThisNull); // true
}
Interactive version: https://run.dlang.io/is/fgT2rS
Anyway, thank you! I didn't know about the feature.
Re: this is null
On Saturday, 9 March 2019 at 20:04:53 UTC, Paul Backus wrote: You can end up with a null `this` reference if you dereference a null pointer to a struct and then call a method on the result. For example: I can but my reference is not null before calling. Take a look at the line of code [0]. There is a check before the line. https://github.com/ANtlord/deadmemory/blob/master/src/deadmemory/mem.d#L20 [0]
Re: this is null
On Saturday, 9 March 2019 at 19:18:38 UTC, ANtlord wrote:
Hello everyone! I've encountered the problem which I already
encountered before. Unfortunately, I had no time in the
previous time to report and to talk about it. So I decided to
play making my own "malloc" function in pure D (betterC) at
this time. And I encountered the issue one more time. `this`
can be null. How? Please take a look at my project [0]. It gets
the current heap break and tries to increase via a free list.
So the segfault I meet happens there [1]. Tell me, please. What
do I wrong?
[0] https://github.com/ANtlord/deadmemory
[1]
https://github.com/ANtlord/deadmemory/blob/master/src/deadmemory/freelist.d#L56
You can end up with a null `this` reference if you dereference a
null pointer to a struct and then call a method on the result.
For example:
struct S
{
bool isThisNull() { return is null; }
}
void main()
{
import.std.stdio;
S* p = null;
writeln((*p).isThisNull); // true
}
Interactive version: https://run.dlang.io/is/fgT2rS
Re: Phobos in BetterC
On Saturday, 9 March 2019 at 17:14:37 UTC, 9il wrote: It was fixed to be used in BetterC. If it still does not work you can open an issue and ping me (@9il). That is awesome. I suppose support for betterC is only from v3 upwards?
Re: Make Dub output *.di files
On Saturday, 9 March 2019 at 19:08:22 UTC, bitwise wrote: On Saturday, 9 March 2019 at 18:39:29 UTC, bitwise wrote: Is it possible to get Dub to output import headers for compiled D files? I found this, which almost works: "dflags": [ "-H", "-Hdimport", "-op" ] The only problem is that Dub runs *above* the source directory, resulting in all my import files being nested in /source/.. So can I get Dub to run the compilation from the /source directory instead? Or is there a way to tell Dub to generate the headers for each file some other way? For now, I guess this will work: "dflags": [ "-H", "-Hdimport", "-op" ], "postBuildCommands": [ "mv import/source/root_pkg import/root_pkg", "rm -rf import/source" ] A platform independent solution would be preferred.
this is null
Hello everyone! I've encountered the problem which I already encountered before. Unfortunately, I had no time in the previous time to report and to talk about it. So I decided to play making my own "malloc" function in pure D (betterC) at this time. And I encountered the issue one more time. `this` can be null. How? Please take a look at my project [0]. It gets the current heap break and tries to increase via a free list. So the segfault I meet happens there [1]. Tell me, please. What do I wrong? [0] https://github.com/ANtlord/deadmemory [1] https://github.com/ANtlord/deadmemory/blob/master/src/deadmemory/freelist.d#L56
Re: Make Dub output *.di files
On Saturday, 9 March 2019 at 18:39:29 UTC, bitwise wrote: Is it possible to get Dub to output import headers for compiled D files? I found this, which almost works: "dflags": [ "-H", "-Hdimport", "-op" ] The only problem is that Dub runs *above* the source directory, resulting in all my import files being nested in /source/.. So can I get Dub to run the compilation from the /source directory instead? Or is there a way to tell Dub to generate the headers for each file some other way?
Re: Distinguish float and integer types from string
On Saturday, 9 March 2019 at 18:11:09 UTC, Jacob Shtokolov wrote:w
One of the task was to take a string from STDIN and detect its
type.
The way I'd do this is a very simple loop:
enum Type { String, Float, Int }
if(str.length && str[0] == '-') {
str = str[1 .. $];
}
Type type = str.length ? Type.Int : Type.String;
foreach(ch; str) {
if(ch == '.' && type = Type.Int)
type = Type.Float;
else if(ch < '0' || ch > '9') {
type = Type.String;
break;
}
}
And if you need to support other details, add them on top of
that. For example, exponents on floats may be a second clause
like how I put negative ahead.
You may also choose to use a regular expression though I think
that is overkill for this.
if (data.isNumeric) {
There are several caveats on that isNumeric function: it sees if
something looks like a D numeric literal, which might not be what
you want. For example, isNumeric("1UL") passes because the U and
L suffixes are allowed in D literals...
But I think that's ugly. The thing is that in PHP, for example,
I would do that like this:
```
if (is_integer($data)) {
Simiarly, this also will not od what you want. is_integer("1")
will return false. "1" is of type string. Those functions check
the dynamic type tag, not the contents of a string.
(actually, you arguably can just always return "string" cuz stdin
is basically just a string or a binary stream anyway :P )
PHP's is_numeric returns true for both integer and floating point
things, similarly to D's...
Make Dub output *.di files
Is it possible to get Dub to output import headers for compiled D files?
Distinguish float and integer types from string
Hi,
Recently, I was trying to solve some funny coding challenges
(https://www.techgig.com).
The questions were really simple, but I found it interesting
because the website allows to use D.
One of the task was to take a string from STDIN and detect its
type.
There were a few options: Float, Integer, string and "something
else" (which, I think, doesn't have any sense under the scope of
the task).
Anyway, I was struggling to find a built-in function to
distinguish float and integer types from a string.
I came to the following solution:
```
import std.stdio;
import std.range;
import std.conv;
import std.string;
import std.format;
immutable msg = "This input is of type %s";
void main()
{
string type;
auto data = stdin.byLine.takeOne.front;
if (data.isNumeric) {
type = data.indexOf(".") >= 0 ? "Float" : "Integer";
}
else {
type = "string";
}
writeln(msg.format(type));
}
```
But I think that's ugly. The thing is that in PHP, for example, I
would do that like this:
```
if (is_integer($data)) {
//...do smth
}
else if (is_float($data)) {
//...do smth
}
else {
//...do smth
}
```
I tried to use std.conv.to and std.conv.parse, but found that
they can't really do this. When I call `data.to!int`, the value
of "123.45" will be converted to int!
Is there any built-in way to detect these types?
Thanks!
Re: Phobos in BetterC
On Friday, 8 March 2019 at 09:24:25 UTC, Vasyl Teliman wrote: I've tried to use Mallocator in BetterC but it seems it's not available there: https://run.dlang.io/is/pp3HDq This produces a linker error. I'm wondering why Mallocator is not available in this mode (it would be intuitive to assume that it's working). Also I would like to know what parts of Phobos are available there (e.g. std.traits, std.typecons...). Thanks in advance. Try this package https://github.com/dlang-community/stdx-allocator (v3.0.2) It was fixed to be used in BetterC. If it still does not work you can open an issue and ping me (@9il). Best, Ilya
Re: Phobos in BetterC
On Saturday, 9 March 2019 at 12:42:34 UTC, Sebastiaan Koppe wrote: There might also be the option to use @nogc exceptions (dip 1008), but I am not sure. That won't work as the implementation on DIP1008 cheats the type system but doesn't actually work, i.e. the exceptions are still CG allocated.
Re: Phobos in BetterC
On Friday, 8 March 2019 at 09:24:25 UTC, Vasyl Teliman wrote: Also I would to know what parts of Phobos are available there (e.g. std.traits, std.typecons...). There is no clear rule on which phobos packages work and which don't. It all depends on what underlying features the phobos package uses. Here is the list of what's not allowed in betterC: - Garbage Collection - TypeInfo and ModuleInfo - Classes - Built-in threading (e.g. core.thread) - Dynamic arrays (though slices of static arrays work) and associative arrays - Exceptions - synchronized and core.sync - Static module constructors or destructors Generally anything meta/compile-time works. Packages like std.traits / std.meta / std.range / std.algorithm are not an issue. You would expect std.typecons.tuple to work as well, but it doesn't. If you are doing ctfe, then you are in for a bummer. Because the same restrictions apply there as well. There is supposed to be a workaround by including the ctfe file in question via -I on the command line, but I could never make it work in dub. If you encounter something that doesn't work, there are a couple of options. Sometimes the function you are trying to use is betterC compatible but is inside a package that isn't. Just extract it into a separate file. At other times it is because the struct has a toString method, or throws an exception. Again, copy the relevant part, rip out the toString method and/or replace the exception with an assert (of course, after you make sure the assert doesn't get triggered). There might also be the option to use @nogc exceptions (dip 1008), but I am not sure. If all that isn't possible, you will have to rewrite the thing in question.
Re: Phobos in BetterC
On Friday, 8 March 2019 at 09:24:25 UTC, Vasyl Teliman wrote: I've tried to use Mallocator in BetterC but it seems it's not available there: https://run.dlang.io/is/pp3HDq This produces a linker error. I'm wondering why Mallocator is not available in this mode (it would be intuitive to assume that it's working). Also I would like to know what parts of Phobos are available there (e.g. std.traits, std.typecons...). Thanks in advance. This is really a linker problem, because -betterC doesn't link druntime, and pbobos links druntime. to get around this pass -i=std.experimental.allocator to dmd along with the rest of you usual arguments.
Re: Phobos in BetterC
On Friday, 8 March 2019 at 09:24:25 UTC, Vasyl Teliman wrote: I've tried to use Mallocator in BetterC but it seems it's not available there: https://run.dlang.io/is/pp3HDq This produces a linker error. I'm wondering why Mallocator is not available in this mode (it would be intuitive to assume that it's working). Also I would like to know what parts of Phobos are available there (e.g. std.traits, std.typecons...). Thanks in advance. I would guess it's not available because it was written before betterC mode was a thing and nobody has yet updated it. If you look at spasm on code.dlang.org there is a version you can copy paste that should work in betterC mode if I remember correctly.
Re: Phobos in BetterC
On Friday, 8 March 2019 at 09:24:25 UTC, Vasyl Teliman wrote: I've tried to use Mallocator in BetterC but it seems it's not available there: https://run.dlang.io/is/pp3HDq This produces a linker error. I'm wondering why Mallocator is not available in this mode (it would be intuitive to assume that it's working). Also I would like to know what parts of Phobos are available there (e.g. std.traits, std.typecons...). Thanks in advance. I can’t answer that but you can use C’s malloc directly: https://run.dlang.io/is/fnRFIr Bastiaan.
Re: Aliasing a mixin (or alternative ways to profile a scope)
On Friday, 8 March 2019 at 11:42:11 UTC, Simon wrote: Thanks, this works flawlessly. Out of interest: what is the "enum" doing there? I had the exact same behaviour in a function before, that I only called at compile-time, so why did it complain then? Can I somehow tell the compiler that a function should only be available at compile-time? The enum (which in D is not only for enumerations, but also for "manifest constants") ensures it is evaluated at compile-time, since things are only evaluated at compile-time if they have to. See also Adam D. Ruppe's post in this thread: https://forum.dlang.org/post/blaawtdhljjantvga...@forum.dlang.org
