Re: Non-ugly ways to implement a 'static' class or namespace?
On Friday, 20 January 2023 at 11:28:23 UTC, thebluepandabear
wrote:
Hi,
In Java/C# you can create purely static classes.
These are classes whose methods are all static, the classes
cannot be derived from or instantiated:
```
static class Algo {
void drawLine(Canvas c, Pos from, Pos to) { .. };
}
```
Class in use:
```
Algo.drawLine(new Canvas(), new Pos(5, 3), new Pos(7, 9));
```
But why not have drawLine just be a free function?
```
import bluepandastuff.algo;
auto canvas = new Canvas();
drawLine(canvas, Pos(5, 3), Pos(7, 9));
// Or, using UFCS:
canvas.drawLine(Pos(5, 3), Pos(7, 9));
```
I turned Pos into a struct, seems like a typical value type to me.
Re: Is there such a JSON parser?
On Monday, 2 January 2023 at 21:36:10 UTC, Steven Schveighoffer wrote: On 1/1/23 6:28 PM, torhu wrote: I need to parse some JSON data into various data structures, so I'm looking for a parser based on events or ranges. One that doesn't just load the file and build a data structure that represents the whole thing. So not std.json, at least. It's pretty rough-edged, but https://code.dlang.org/packages/jsoniopipe will do this. It has mechanisms to jump to specific object members, and to rewind to a cached point. It does not use any intermediate representation. -Steve Thank, I can check it out.
Re: Handling CheckBox state changes in DLangUI
On Saturday, 31 December 2022 at 02:40:49 UTC, Daren Scot Wilson wrote: The compiler errors I get are, for no '&' and with '&': Error: function `app.checkbox_b_clicked(Widget source, bool checked)` is not callable using argument types `()` Error: none of the overloads of `opAssign` are callable using argument types `(bool function(Widget source, bool checked))` If checkbox_b_clicked is a non-static nested function or non-static method, taking the address of it should result in a delegate, not a function pointer. You can check what it is like this: writeln(typeid(_b_clicked));
Re: Is there such a JSON parser?
On Monday, 2 January 2023 at 14:56:27 UTC, SealabJaster wrote: Are you asking for a SAX-styled parser for JSON? Yes, I actually want to replace a SAX parser.
Re: Is there such a JSON parser?
On Monday, 2 January 2023 at 05:44:33 UTC, thebluepandabear wrote: You might want to try the following: https://github.com/libmir/asdf I had a look at that, but I think it just loads the whole file into it's own data structure. And then you can use attributes to get it to fill structs with data, but that's too basic for my needs.
Is there such a JSON parser?
I need to parse some JSON data into various data structures, so I'm looking for a parser based on events or ranges. One that doesn't just load the file and build a data structure that represents the whole thing. So not std.json, at least.
Re: How to use version in dub?
On Tuesday, 13 December 2022 at 19:50:15 UTC, torhu wrote:
On Tuesday, 13 December 2022 at 19:28:44 UTC, Leonardo A wrote:
Hello. How to use version in dub?
https://dlang.org/spec/version.html
"The version level and version identifier can be set on the
command line by the -version"
I tried everything but noting.
In SDL syntax, either at the top level, in a configuration, or
build type:
```
versions "something" "other"
```
To be more clear: When using dub you need to put this in the dub
file, dub.sdl or dub.json. If you want to be able to choose from
the command line, use a configuration:
```
configuration "something" {
versions "something"
}
```
Then you can do:
```
dub build -c=something
```
Re: How to use version in dub?
On Tuesday, 13 December 2022 at 19:28:44 UTC, Leonardo A wrote: Hello. How to use version in dub? https://dlang.org/spec/version.html "The version level and version identifier can be set on the command line by the -version" I tried everything but noting. In SDL syntax, either at the top level, in a configuration, or build type: ``` versions "something" "other" ```
Re: aa.keys, synchronized and shared
On Monday, 14 November 2022 at 07:57:16 UTC, Kagamin wrote:
This works for me:
```
shared SyncAA!(string,string) saa;
void f()
{
saa=new shared SyncAA!(string,string)("1","2");
saa.keys();
saa["12"]="34";
saa.remove("12");
}
```
The strange error message I got was because I initialized the
variable at module level, that doesn't work when you have a
constructor. It worked when I moved it into a module constructor.
Re: aa.keys, synchronized and shared
On Friday, 11 November 2022 at 14:19:31 UTC, Kagamin wrote:
Try this:
```
private:
V[K] sharedTable;
ref inout(V[K]) unsharedTable() inout
{
return *cast(inout(V[K])*)
}
```
Thanks, that worked! Feels like programming in C, though. If I
could figure out how to initialize the AA explicitly, I could
also remove the ref here. If I just remove the ref, the AA is
always null. If I try to initialize it in the constructor, I get
this:
src\syncaa.d(11,5): Error: `_d_monitorenter` cannot be
interpreted at compile time, because it has no available source
code
No idea why, it seems to happen if I try to use the AA in the
constructor at all. Even when I just do `data_.remove(K.init);`
I also tried DMD 2.101.0-rc.1, using the new `new V[K]` syntax,
same error there.
Re: aa.keys, synchronized and shared
On Thursday, 10 November 2022 at 21:55:26 UTC, torhu wrote: I'm trying to make a more thread-safe wrapper for AA's: ``` synchronized final class SyncAA(K, V) /// I chose to fix this by just using `synchronized (this)` inside each method instead, for now. Still interested in cleaner solutions, but I guess synchronized/shared is a bit of a rabbit hole...
aa.keys, synchronized and shared
I'm trying to make a more thread-safe wrapper for AA's:
```
synchronized final class SyncAA(K, V) ///
{
///
V opIndex(K key) { return data_[key]; }
///
V opIndexAssign(V value, K key) { return data_[key] = value; }
///
K[] keys() const { return data_.keys; }
///
void remove(K key) { data_.remove(key); }
/// There is no `in` operator, it would not be thread-safe.
V get(K key, lazy V defaultValue=V.init)
{
auto p = key in data_;
return p ? *p : defaultValue;
}
///
int opApply(scope int delegate(inout ref V) dg) const
{
int result = 0;
foreach (value; data_) {
result = dg(value);
if (result)
break;
}
return result;
}
///
int opApply(scope int delegate(K, inout ref V) dg) const
{
int result = 0;
foreach (key, value; data_) {
result = dg(key, value);
if (result)
break;
}
return result;
}
private:
V[K] data_;
}
```
In another file:
`__gshared serverListCache = new SyncAA!(string, ServerList);`
I'm using `keys` in a regular function, this is the error i get:
C:\prog\dmd\windows\bin\..\..\src\druntime\import\object.d(3245,36): Error:
cannot implicitly convert expression `aa` of type
`shared(const(ServerList[string]))` to `const(shared(ServerList)[string])`
src\syncaa.d(17,36): Error: template instance
`object.keys!(shared(const(ServerList[string])),
shared(const(ServerList)), string)` error instantiating
src\serveractions.d(45,33):instantiated from here:
`SyncAA!(string, ServerList)`
src\serveractions.d(50,17): Error: `shared` `const` method
`syncaa.SyncAA!(string, ServerList).SyncAA.keys` is not callable
using a non-shared mutable object
Error C:\prog\dmd\windows\bin\dmd.exe failed with exit code 1.
Re: Doubt about char.min/max == typeid(char)
On Friday, 7 October 2022 at 00:13:59 UTC, matheus wrote:
Hi,
Could anyone please tell me why the properties of min/max of a
char returns a "char type" and not a value as an int?
Well, why whould the highest and lowest values of a type be of a
different type..?
```d
import std;
void func(char x) { writeln("It's a char"); }
void func(int x) { writeln("It's an int"); }
void func(double x) { writeln("It's a double"); }
void main(){
func(char.min);
}
```
Re: Replacing tango.text.Ascii.isearch
On Thursday, 6 October 2022 at 21:36:48 UTC, rassoc wrote:
And what kind of testing was that? Mind to share? Because I did
the following real quick and wasn't able to measure a "two
orders of magnitude" difference. Sure, the regex version came
on top, but they were both faster than the ruby baseline I
cooked up.
Originally I just loaded a one megabyte file and searched the
whole thing. I changed it to split it into (40 000) lines
instead, regex is about ten times faster then. I compile with
-release -O -inline. Here is the second version:
```d
import std;
import std.datetime.stopwatch;
enum FILE = "test.lst";
string text;
string needle;
void test(bool delegate(string haystack) dg)
{
auto sw = StopWatch(AutoStart.yes);
int counter = 0;
foreach (line; lineSplitter(text)) {
if (dg(line))
counter++;
}
sw.stop();
writefln("%s", sw.peek());
writefln("counter: %s", counter);
}
void main(char[][] args)
{
enforce(args.length > 1, "Need a needle argument.");
text = cast(string)read(FILE);
needle = args[1].idup;
auto re = regex(to!string(escaper(needle)), "i");
string needleLower = needle.toLower();
test((h) => !!h.matchFirst(re));
test((h) => h.asLowerCase().canFind(needleLower));
}
```
Re: Replacing tango.text.Ascii.isearch
On Wednesday, 5 October 2022 at 17:29:25 UTC, Steven
Schveighoffer wrote:
```d
bool isearch(S1, S2)(S1 haystack, S2 needle)
{
import std.uni;
import std.algorithm;
return haystack.asLowerCase.canFind(needle.asLowerCase);
}
```
untested.
-Steve
I did some basic testing, and regex was two orders of magnitude
faster. So now I know, I guess.
Re: Replacing tango.text.Ascii.isearch
On Wednesday, 5 October 2022 at 20:45:55 UTC, torhu wrote: On Wednesday, 5 October 2022 at 20:40:46 UTC, torhu wrote: Am I doing something wrong here? Right, you can instantiate structs without arguments. It's been ten years since I last used D, I was thinking of structs like if they were classes. I think there should be sensible default here, seems like an easy trap to remove.
Re: Replacing tango.text.Ascii.isearch
On Wednesday, 5 October 2022 at 20:40:46 UTC, torhu wrote: Am I doing something wrong here? Right, you can instantiate structs without arguments. It's been ten years since I last used D, I was thinking of structs like if they were classes.
Re: Replacing tango.text.Ascii.isearch
On Wednesday, 5 October 2022 at 17:29:25 UTC, Steven
Schveighoffer wrote:
[...]
I wanted to do some quick benchmarking to figure out what works.
When I run this:
```d
import std.stdio;
import std.datetime.stopwatch;
void main()
{
auto sw = StopWatch();
sw.stop();
writeln(sw.peek().toString());
}
```
It prints this:
2 weeks, 6 days, 9 hours, 34 minutes, 43 secs, 214 ms, 946 ╬╝s,
and 7 hnsecs
Am I doing something wrong here?
Replacing tango.text.Ascii.isearch
I need a case-insensitive check to see if a string contains another string for a "quick filter" feature. It should preferrably be perceived as instant by the user, and needs to check a few thousand strings in typical cases. Is a regex the best option, or what would you suggest?
Re: Template function alias that leaves out the last type parameter
On Wednesday, 28 September 2022 at 12:43:52 UTC, rassoc wrote:
On 9/28/22 02:04, torhu via Digitalmars-d-learn wrote:
Thank you, works like a charm!
It does? How are you formatting `info("foo", 'a', 42)` inside
the template if I may ask?
It works like writefln, so that example would not compile. I
forgot to make the format string explicit, I probably should have
done that.
```
private template _messageBox(string title, int style)
{
void _messageBox(T...)(T args)
{
messageBox(format(args), title, style);
}
}
```
Re: Template function alias that leaves out the last type parameter
On Tuesday, 27 September 2022 at 23:18:06 UTC, Adam D Ruppe wrote: On Tuesday, 27 September 2022 at 22:39:52 UTC, torhu wrote: How would I achieve something like this, do I have to turn the aliases into functions? You can write it out long-form with two steps like this: Thank you, works like a charm!
Re: Template function alias that leaves out the last type parameter
On Tuesday, 27 September 2022 at 22:39:52 UTC, torhu wrote:
How would I achieve something like this, do I have to turn the
aliases into functions?
```d
void _messageBox(string title, int style, T...)(T args)
{
string s = format(args);
/* etc... */
}
alias _messageBox!(APPNAME, SWT.ICON_INFORMATION) info;
alias _messageBox!("Warning", SWT.ICON_WARNING) warning;
alias _messageBox!("Error", SWT.ICON_ERROR) error;
```
I should mention that I am really looking for a Phobos 2 way of
achieving what I currently do, which is this:
```d
void _messageBox(string title, int style)(...)
{
char[] msg;
void f(dchar c) { encode(msg, c); }
doFormat(, _arguments, _argptr);
messageBox(cast(string)msg, title, style);
}
```
Template function alias that leaves out the last type parameter
How would I achieve something like this, do I have to turn the
aliases into functions?
```d
void _messageBox(string title, int style, T...)(T args)
{
string s = format(args);
/* etc... */
}
alias _messageBox!(APPNAME, SWT.ICON_INFORMATION) info;
alias _messageBox!("Warning", SWT.ICON_WARNING) warning;
alias _messageBox!("Error", SWT.ICON_ERROR) error;
```
