Re: std.datetime & timzone specifier: 2018-11-06T16:52:03+01:00
On Sunday, 8 March 2020 at 17:28:33 UTC, Robert M. Münch wrote:
On 2020-03-07 12:10:27 +, Jonathan M Davis said:
DateTime dt =
DateTime.fromISOExtString(split("2018-11-06T16:52:03+01:00",
regex("\\+"))[0]);
IMO such a string should be feedable directly to the function.
You just need to use SysTime.fromISO*String functions for that,
as DateTime does't work with timezones, SysTime do.
Re: std.datetime & timzone specifier: 2018-11-06T16:52:03+01:00
On Sunday, 8 March 2020 at 17:28:33 UTC, Robert M. Münch wrote:
[...]
But I have to do:
DateTime dt =
DateTime.fromISOExtString(split("2018-11-06T16:52:03+01:00",
regex("\\+"))[0]);
You don't need a regex. split (..., '+') seems to suffice here.
IMO such a string should be feedable directly to the function.
It took me less than an hour to figure out how to provide a local
version of std.datetime named local.datetime:
```local/datetime.d
module local.datetime;
public import std.datetime;
struct DateTime {
std.datetime.DateTime dt;
alias dt this;
static DateTime fromISOExtString (string s)
{
import std.array;
auto arr = split (s, '+');
import std.exception;
enforce (arr.length > 0);
return DateTime (dt.fromISOExtString (arr[0]));
}
}
```
usage: import local.datetime instead of import std.datetime.
Re: Converting Lua source to D
On Saturday, 7 March 2020 at 01:14:14 UTC, Jesse Phillips wrote: Now I should look at getting the CI up and Test failure fixed. Test failures were my local system and related to the stack overflow tests. I have the build pipeline up and running but hit a couple of snags. https://github.com/JesseKPhillips/lua/runs/493866555?check_suite_focus=true * Couldn't use dpp in the build because I couldn't install libclang-dev on the runner (ubuntu repository issue) * The compiler couldn't locate libphobos I think I'll be able to make use of dpp locally though.
Re: static foreach / How to construct concatenated string?
On 2020-03-07 16:41:47 +, MoonlightSentinel said:
You can use an anonymous lambda to build the string in CTFE:
--
struct S {
int a;
bool b;
}
import std;
enum string sql = {
string s = "CREATE TABLE data(";
static foreach(f; FieldNameTuple!S) {
s ~= f ~ ",";
}
s ~= ");";
return s;
} ();
pragma(msg, sql);
--
This prints "CREATE TABLE data(a, b);"
You can get rid of the enum und the static and it will work too.
--
Robert M. Münch
http://www.saphirion.com
smarter | better | faster
Re: How to use sets in D?
On Friday, 7 February 2020 at 19:37:08 UTC, mark wrote: I am porting code from other languages to D as part of learning D, and I find I've used sets quite a lot. AFAIK D doesn't have a built-in set type or one in the std. lib. However, I've been perfectly successfully using int[E] where E is my ElementType, and adding with set[element] = 0. I mostly only need add, remove, iteration, and in, with uniqueness what I care most about. I know I could use bool[E] and set[element] = false, or I suppose container.rbtree. Would either of these--or something else built-in or in the std. lib.--be better? I think I've usually used the associative arrays, but I also think I tend to avoid using this approach but couldn't quite remember what I do instead. I believe I have started just using an array. arr ~= addMyData; arr.sort.uniq Then I make use of the algorithms here. https://dlang.org/phobos/std_algorithm_setops.html
Re: Just a Reminder...
On Monday, 24 February 2020 at 17:47:37 UTC, Ron Tarrant wrote: In case you thought the GtkDcoding blog announcements have stopped, I just want to let you know that starting with #0101, they'll be made in the Announce sub-forum from now on. This is where they were originally supposed to be made, but because I got the wrong end of the stick last year, I ended up making them here in Learn. [...] I love your blog posts, thank you again.
Re: Can't compile dlangui
On Friday, 7 February 2020 at 14:25:05 UTC, Jan Hönig wrote: On Friday, 7 February 2020 at 12:04:10 UTC, A.Perea wrote: [...] I am afraid that dlangui and dlangide is currently not maintained, since i can reproduce the error as well. If you are looking for a good editor for D: I am using VisualStudioCode with the code-d plugin. If you don't like Microsoft's calling home features, you can go for Codium: https://vscodium.com/ Thank you for that vscodium tip! Ditched visual studio code just now and replaced it with vscodium.
Re: A small D/GtkD example game
On Monday, 24 February 2020 at 19:18:24 UTC, mark wrote: I've just completed a small D/GtkD game. It might be useful for others trying to learn GtkD since it is only just over 1000 lines, yet shows how to create a dialog-style app with a modal dialog and a modeless dialog, and a custom drawn widget, as well as keyboard and mouse handling. The source (and a 64-bit Windows binary) is here: https://github.com/mark-summerfield/gravitate-d I'm posting to the Learn forum because I'm just a D beginner, so felt that using the announce list would be a bit presumptuous. Thanks! Much appreciated, perfect for a beginner as me.
Re: std.datetime & timzone specifier: 2018-11-06T16:52:03+01:00
On 2020-03-07 12:10:27 +, Jonathan M Davis said:
I take it that you're asking why you don't get the time zone as part of the
string when you call one of the to*String functions?
The problem is, the from* functions give an error, that this is not an
ISO date.
I get this in an XML response and extract the datetime:
But I have to do:
DateTime dt =
DateTime.fromISOExtString(split("2018-11-06T16:52:03+01:00",
regex("\\+"))[0]);
IMO such a string should be feedable directly to the function.
--
Robert M. Münch
http://www.saphirion.com
smarter | better | faster
Re: static foreach / How to construct concatenated string?
On 2020-03-07 16:41:47 +, MoonlightSentinel said:
On Saturday, 7 March 2020 at 16:30:59 UTC, Robert M. Münch wrote:
Is this possible at all?
You can use an anonymous lambda to build the string in CTFE:
--
struct S {
int a;
bool b;
}
import std;
enum string sql = {
string s = "CREATE TABLE data(";
static foreach(f; FieldNameTuple!S) {
s ~= f ~ ",";
}
s ~= ");";
return s;
} ();
pragma(msg, sql);
--
This prints "CREATE TABLE data(a, b);"
Nice... is the enum a so called "manifest constant" for which the
initializer is evaluated at compile time?
OT: The pragma seems to print the string twice... at least here on my side.
OT2: Looks like I have to read through the language spec again... and
most likely over and over again, to have all these tricks at my
finger-tips.
--
Robert M. Münch
http://www.saphirion.com
smarter | better | faster
Re: How to use sets in D?
On Sunday, 8 March 2020 at 08:43:10 UTC, mark wrote: Here are some timings ... [...] #!/usr/bin/env rdmd Please remember that performance testing is not trivial. At the very least, you should be testing optimized code (-O) and preferably with LDC or GDC because they have a much stronger optimizer than DMD. Also, `assert` is not a good way to check something in performance testing code. See https://forum.dlang.org/thread/bpbyhmrsfzirfqggn...@forum.dlang.org -Johan
Re: How to use sets in D?
I use sets a lot and am now working on a program that will need
to hold sets of 65,000+ items, so I thought I do some timings for
the different approaches.
Here are some timings (uset uses the AA Unit approach, tset uses
an rbtree, and aset uses an AA with bool values):
$ ./sets.d
size 50,000
uset 1 ms, 340 μs, and 8 hnsecs
tset 4 ms, 637 μs, and 1 hnsec
aset 1 ms, 402 μs, and 6 hnsecs
$ ./sets.d
size 100,000
uset 2 ms, 338 μs, and 4 hnsecs
tset 12 ms, 262 μs, and 6 hnsecs
aset 2 ms and 991 μs
$ ./sets.d
size 200,000
uset 5 ms, 971 μs, and 5 hnsecs
tset 30 ms, 675 μs, and 5 hnsecs
aset 6 ms, 74 μs, and 6 hnsecs
$ ./sets.d
size 400,000
uset 11 ms, 823 μs, and 4 hnsecs
tset 74 ms, 146 μs, and 2 hnsecs
aset 12 ms, 560 μs, and 5 hnsecs
What seems pretty clear is that for my purposes (checking
presence or absence of membership in a set), AAs are much faster
than rbtrees. (This is to be expected since if an AA uses a hash
is should be O(1) vs O(lg n) for an rbtree).
Here is the test code I used:
#!/usr/bin/env rdmd
enum SIZE = 400_000;
enum SUB_SIZE = SIZE / 10;
enum MIN_LEN = 10;
enum MAX_LEN = 50;
enum AZ = "abcdefghijklmnopqrstuvwxyz";
void main() {
import std.stdio: writefln;
auto data = Data.populate();
auto sets = Sets(data.words);
writefln("size %,d", SIZE);
check(sets.uset, data.present, data.absent, "uset");
check(sets.tset, data.present, data.absent, "tset");
check(sets.aset, data.present, data.absent, "aset");
}
struct Sets {
import std.container.rbtree: RedBlackTree;
alias Unit = void[0];
enum unit = Unit.init;
Unit[string] uset;
RedBlackTree!string tset;
bool[string] aset;
this(string[] words) {
tset = new RedBlackTree!string;
foreach (word; words) {
uset[word] = unit;
tset.insert(word);
aset[word] = false;
}
}
}
struct Data {
string[] words;
string[] present;
string[] absent;
static Data populate() {
Data data;
for (int i = 0; i < SIZE; i++) {
auto word = makeWord;
data.words ~= word;
if (data.present.length < SUB_SIZE)
data.present ~= word;
if (data.absent.length < SUB_SIZE)
data.absent ~= word ~ "9";
}
return data;
}
}
string makeWord() {
import std.random: randomCover, uniform;
import std.range: take;
import std.string: join, split;
enum AZS = (AZ ~ AZ ~ AZ ~ AZ ~ AZ ~ AZ).split("");
return randomCover(AZS).take(uniform(MIN_LEN,
MAX_LEN)).join("");
}
void check(T)(T set, string[] present, string[] absent, string
name) {
import std.datetime.stopwatch: AutoStart, StopWatch;
import std.stdio: writeln;
auto timer = StopWatch(AutoStart.yes);
foreach (string p; present)
assert(p in set);
foreach (string a; absent)
assert(a !in set);
writeln(name, " ", timer.peek);
}
