Re: std.net.curl.HTTP: can't download more than 3.6K
Nevermind, it was my fault. I fixed my problem by appending the received buffer to my data buffer instead of overwriting my data buffer each time.
Re: Difference between using `import` with/without the colon
On Sunday, 19 March 2023 at 08:47:32 UTC, Basile B. wrote: On Sunday, 19 March 2023 at 07:20:17 UTC, Jeremy wrote: [...] The colon-form, aka "selective import" has for effect 1. to create a local alias so this can indeed speedup symbol lookups in the sense that search will succeed before looking in the scope of the imports. 2. to make non-selected symbols, i.e not listed in the colon right hand side, in the import not available. Note that using both makes no sense, but I guess you did that to express more clearly what you meant. Ah, that makes sense. Thank you!
Re: alias Error: need 'this'
On 3/19/23 06:49, bomat wrote:
> I can live with the `static`
> solution, I guess.
If you could, you would define it 'static' anyway. :) Because you highly
likely needed a distinct 'variableWithALongName' member for each
MyStruct object, that wouldn't work.
> Shouldn't it be the exact same underlying mechanism?
I don't know the answer. Luckily, what you describe is available in
another form in the language:
ref alias2() {
return myStruct.memberWithALongName;
}
Ali
Unrelated: I find 'myObject' a more correct name for a variable because
if 'struct' is the definition of a type, 'myStruct' attempts to convey a
misleading meaning.
Re: alias Error: need 'this'
On Sunday, 19 March 2023 at 13:49:36 UTC, bomat wrote: Thanks for the suggested workaround, I can live with the `static` solution, I guess. I still don't understand why it's necessary, though. Since a `struct` is a value type and, as I understand it, stack allocated, what difference does it make to the compiler whether I alias `variableWithALongName` or `myStruct.memberWithALongName`? Shouldn't it be the exact same underlying mechanism? Thanks and regards bomat D aliases are for symbols, but what you try to alias is an expression. You might feel that what you request may work, but that's only a very particular case. Generally expressions cannot be aliased because without context they become polymorphic (or erather polysemous).
Re: Traverse a DList and insert / remove in place?
ok there is the issue of not knowing how to traverse the list
after removing the current element (=> the one that came after of
course). But how about even just keeping a pointer (range) to
'element' that can be used after the list has been traversed in
full to use in remove / insertAfter?
I think I can achieve this with associative arrays (below) but it
seems overkill to use an associative effectively as a DList?
```d
struct myType{
int id;
int prev, next; // id of prev and next
// [...] other stuff
this(int id_, int prev_, int next_)
{
//[...]
}
}
myType[int] list; // key = id
int[] to_remove;
myType[] to_add;
foreach(elem; list)
{
// [...] do something long and complicated with elem, throw a
random number rand
if(rand < 0.5)
to_remove ~= elem.id; // flag for removal
else
to_add ~= myType(some_new_id, elem.id, elem.next); // add
new elem after current
}
foreach(elem; to_add)
list[elem.id] = elem;
foreach(id; to_remove)
{
// reconnect: prev's next to next, and next's prev to prev
list[list[id].prev].next = list[id].next;
list[list[id].next].prev = list[id].prev;
list.remove(id);
}
```
Re: alias Error: need 'this'
On Sunday, 19 March 2023 at 12:29:19 UTC, Salih Dincer wrote: It is possible to achieve the convenience you want to achieve in 2 ways. One of them is to use a static member but if not, to use an alias inside the container. Thanks for the suggested workaround, I can live with the `static` solution, I guess. I still don't understand why it's necessary, though. Since a `struct` is a value type and, as I understand it, stack allocated, what difference does it make to the compiler whether I alias `variableWithALongName` or `myStruct.memberWithALongName`? Shouldn't it be the exact same underlying mechanism? Thanks and regards bomat
Traverse a DList and insert / remove in place?
Say I have a DList. I am looking for a vanilla way to
insert/remove elements in place while traversing that list.
```d
import std.container : DList;
struct myType{
int id;
// [...] other stuff
}
auto list = DList!myType();
// [...] populate list with elements
```
To remove the element with id=3 I can do:
```d
list.linearRemove(list[].find!(a => a.id==3).take(1));
```
but according to [this
post](https://forum.dlang.org/post/mailman.3110.1356864469.5162.digitalmar...@puremagic.com) linearRemove might be less efficient than remove and remove can't be used. Also in the example above, finding the needle is easy but my case would involve more complicated scenarios that I am relunctant to bury into find's predicate.
I would like to do something like traversing a DList, operating
on the current element, and potentially removing that element or
inserting a new one before/after it - an easy operation if you
code a DList yourself. Maybe I missed something?
```d
// Traverse and operate on current element
foreach(element; list)
{
// [...] do something long and complicated with m, throw a
random number rand
if(rand < 0.5)
list.removeInPlace(); // remove 'element'
else
list.insertInPlace(myType(...)); // insert a new element
"here" (before/after 'element')
}
```
Any way to achieve this simply with D? E.g. is there a way to
extract the 'reading head' of a list being traversed and to use
that head as a range into the remove, insertAfter, insertBefore
functions?
Re: alias Error: need 'this'
On Sunday, 19 March 2023 at 11:52:50 UTC, bomat wrote:
It works fine with the `int` variable, but with the struct
member I get a compilation error:
```
Error: need `this` for `memberWithALongName` of type `int`
```
What is that supposed to mean?
It is possible to achieve the convenience you want to achieve in
2 ways. One of them is to use a static member but if not, to use
an alias inside the container. For example:
```d
struct MyStruct
{
int memberWithALongName;
alias ln = memberWithALongName;
static string str;
}
void main()
{
auto myStruct = MyStruct(1);
myStruct.ln = 2;
alias alias2 = MyStruct.str;
alias2 = "2";
import std.conv : text;
assert(myStruct.ln.text == alias2);
}
```
SDB@79
alias Error: need 'this'
Hi,
I read about aliases today and thought it would be handy for
shortening repeated access to struct members.
However, I'm clearly missing something.
Here's some example code:
```
int variableWithALongName = 42;
alias alias1 = variableWithALongName;
alias1 = 43;
assert(variableWithALongName == 43);
struct MyStruct
{
int memberWithALongName;
}
MyStruct myStruct;
myStruct.memberWithALongName = 42;
alias alias2 = myStruct.memberWithALongName;
alias2 = 43; // does not compile, see below
assert(myStruct.memberWithALongName == 43);
```
It works fine with the `int` variable, but with the struct member
I get a compilation error:
```
Error: need `this` for `memberWithALongName` of type `int`
```
What is that supposed to mean?
Thanks
bomat
Re: Difference between using `import` with/without the colon
On Sunday, 19 March 2023 at 07:20:17 UTC, Jeremy wrote: Hello, is there any difference at all between the following lines, as an example: ```d import std.regex; import std.regex : matchFirst; ``` What technical differences does it make (except for having the identifier available), using the colon? Does it make any speed/optimization changes or am I better off just importing the whole module? The colon-form, aka "selective import" has for effect 1. to create a local alias so this can indeed speedup symbol lookups in the sense that search will succeed before looking in the scope of the imports. 2. to make non-selected symbols, i.e not listed in the colon right hand side, in the import not available. Note that using both makes no sense, but I guess you did that to express more clearly what you meant.
Difference between using `import` with/without the colon
Hello, is there any difference at all between the following lines, as an example: ```d import std.regex; import std.regex : matchFirst; ``` What technical differences does it make (except for having the identifier available), using the colon? Does it make any speed/optimization changes or am I better off just importing the whole module?
std.net.curl.HTTP: can't download more than 3.6K
Hello, I'm new to D and the `std.net.curl` library. I'm using the `HTTP` struct because I need to set headers for an API, and most of the time, I can only download 3.6 kilobytes at a time. Would this be a problem with the library not following redirects or something else? I'm not really sure what it could be, so could someone help me with this?
