Re: Deprecation: foreach: loop index implicitly converted from size_t to int
A horrible alternative would be to use `alias` on `size_t` to
make up a new pseudo-type that is more aligned with the code
logic.
```
alias integer = size_t;
import std.stdio : writefln;
void main() {
auto arr = [
[5, 15], // 20
[2, 3, 2, 3], // 10
[3, 6, 2, 9], // 20
];
foreach (integer i, row; arr)
{
double total = 0.0;
foreach (e; row)
total += e;
auto avg = total / row.length;
writefln("AVG [row=%d]: %.2f", i, avg);
}
}
```
Re: Deprecation: foreach: loop index implicitly converted from size_t to int
Well all these proposals to `int` index like `size_t` and `const typeof(arr.length)` are cryptic and less readable and less straightforward in comparison to how it used to be. Feels like horrible decision if the language is suppose to be somewhat futureproof. The `int` was simple, straighforward and great. These suggestions feel like some `C++` all over again.
Re: Deprecation: foreach: loop index implicitly converted from size_t to int
On Friday, 3 May 2024 at 15:19:13 UTC, user1234 wrote:
On Friday, 3 May 2024 at 14:59:57 UTC, BoQsc wrote:
On Friday, 3 May 2024 at 13:18:02 UTC, user1234 wrote:
[...]
So how would you update this example, what is the right index
type here to choose?
```
import std.stdio : writefln;
void main() {
auto arr = [
[5, 15], // 20
[2, 3, 2, 3], // 10
[3, 6, 2, 9], // 20
];
foreach (i, row; arr)
{
double total = 0.0;
foreach (e; row)
total += e;
auto avg = total / row.length;
writefln("AVG [row=%d]: %.2f", i, avg);
}
}
```
Example taken from
https://tour.dlang.org/tour/en/basics/foreach
Isn't that obvious ?
```d
foreach (const size_t i, row; arr)
```
`arr` is not a static array, it is a dynamic one, consequently
its `.length` type is `size_t`, even if you have the feeling
that, in the present situation, `int` bitwidth would be
sufficient.
even better:
```d
foreach (const typeof(arr.length) i, row; arr)
```
Otherwise I respect your POV, it's just that here I have no
problem with the way that works. I dont see any issue with the
type system. D type system is static, strong, but optionally
inferred. And that's it.
Re: Deprecation: foreach: loop index implicitly converted from size_t to int
On Friday, 3 May 2024 at 14:59:57 UTC, BoQsc wrote:
On Friday, 3 May 2024 at 13:18:02 UTC, user1234 wrote:
On Friday, 3 May 2024 at 10:50:03 UTC, BoQsc wrote:
[...]
**You can specify the index type, just choose the right one.**
For now there's a deprecation message but after some while
you'll get a proper error message, e.g _"index type for arr
must be of type T because arr.length type is T"_.
What's is happening now is to help people updating their code
and prevent abrupt breakages.
So how would you update this example, what is the right index
type here to choose?
```
import std.stdio : writefln;
void main() {
auto arr = [
[5, 15], // 20
[2, 3, 2, 3], // 10
[3, 6, 2, 9], // 20
];
foreach (i, row; arr)
{
double total = 0.0;
foreach (e; row)
total += e;
auto avg = total / row.length;
writefln("AVG [row=%d]: %.2f", i, avg);
}
}
```
Example taken from https://tour.dlang.org/tour/en/basics/foreach
Isn't that obvious ?
```d
foreach (const size_t i, row; arr)
```
`arr` is not a static array, it is a dynamic one, consequently
its `.length` type is `size_t`, even if you have the feeling
that, in the present situation, `int` bitwidth would be
sufficient.
Re: Deprecation: foreach: loop index implicitly converted from size_t to int
On Friday, 3 May 2024 at 13:18:02 UTC, user1234 wrote:
On Friday, 3 May 2024 at 10:50:03 UTC, BoQsc wrote:
Why am I forced to visit this D Lang thread, why this
deprecation warning still appears in my console window in the
latest version of DMD. Does not make any sense from the
developer's perspective to show this warning and pollute the
already polluted logging entries of the compiler. How am I
suppose to program anything effectively if half of the screen
are some nonsensical deprecation warnings without guidance or
sane explanations.
This is not better
```
foreach (i, row; arr)
```
than
```
foreach (int i, row; arr)
```
Hides the datatype and makes the D language appear in-explicit
and annoying.
What is this language becoming. A completely weak typed
language or something?
I would use JavaScript if I would want that. How are we
suppose to make whole sane Operating Systems with such
syntaxes. Do everyone just enjoy having bugs with some
implicit size_t, or do everyone just enjoy deprecation
warnings in their logging systems when there are way more
important problems to solve, that are actually project related.
**You can specify the index type, just choose the right one.**
For now there's a deprecation message but after some while
you'll get a proper error message, e.g _"index type for arr
must be of type T because arr.length type is T"_.
What's is happening now is to help people updating their code
and prevent abrupt breakages.
So how would you update this example, what is the right index
type here to choose?
```
import std.stdio : writefln;
void main() {
auto arr = [
[5, 15], // 20
[2, 3, 2, 3], // 10
[3, 6, 2, 9], // 20
];
foreach (i, row; arr)
{
double total = 0.0;
foreach (e; row)
total += e;
auto avg = total / row.length;
writefln("AVG [row=%d]: %.2f", i, avg);
}
}
```
Example taken from https://tour.dlang.org/tour/en/basics/foreach
Re: Deprecation: foreach: loop index implicitly converted from size_t to int
On Friday, 3 May 2024 at 10:50:03 UTC, BoQsc wrote: Why am I forced to visit this D Lang thread, why this deprecation warning still appears in my console window in the latest version of DMD. Does not make any sense from the developer's perspective to show this warning and pollute the already polluted logging entries of the compiler. How am I suppose to program anything effectively if half of the screen are some nonsensical deprecation warnings without guidance or sane explanations. This is not better ``` foreach (i, row; arr) ``` than ``` foreach (int i, row; arr) ``` Hides the datatype and makes the D language appear in-explicit and annoying. What is this language becoming. A completely weak typed language or something? I would use JavaScript if I would want that. How are we suppose to make whole sane Operating Systems with such syntaxes. Do everyone just enjoy having bugs with some implicit size_t, or do everyone just enjoy deprecation warnings in their logging systems when there are way more important problems to solve, that are actually project related. You can specify the index type, just choose the right one. For now there's a deprecation message but after some while you'll get a proper error message, e.g _"index type for arr must be of type T because arr.length type is T"_. What's is happening now is to help people updating their code and prevent abrupt breakages.
Re: Deprecation: foreach: loop index implicitly converted from size_t to int
Why am I forced to visit this D Lang thread, why this deprecation warning still appears in my console window in the latest version of DMD. Does not make any sense from the developer's perspective to show this warning and pollute the already polluted logging entries of the compiler. How am I suppose to program anything effectively if half of the screen are some nonsensical deprecation warnings without guidance or sane explanations. This is not better ``` foreach (i, row; arr) ``` than ``` foreach (int i, row; arr) ``` Hides the datatype and makes the D language appear in-explicit and annoying. What is this language becoming. A completely weak typed language or something? I would use JavaScript if I would want that. How are we suppose to make whole sane Operating Systems with such syntaxes. Do everyone just enjoy having bugs with some implicit size_t, or do everyone just enjoy deprecation warnings in their logging systems when there are way more important problems to solve, that are actually project related.
Re: Deprecation: foreach: loop index implicitly converted from size_t to int
On Friday, January 18, 2019 8:34:22 AM MST Michael via Digitalmars-d-learn wrote: > On Friday, 18 January 2019 at 13:29:29 UTC, Adam D. Ruppe wrote: > > On Friday, 18 January 2019 at 12:27:17 UTC, Michael wrote: > >> This, to be, looks like quite the explicit conversion, no? > > > > Yeah, I agree. But the language is silly. I just leave the type > > out of foreach and explicitly cast it inside the body. > > Thank you all for the concise explanations and suggestions, I > think that's fairly straightforward. I thought perhaps I was > doing the sensible thing of dealing with the conversion inside > the foreach statement, but I guess not! Well, you were really doing the equivalent of simply declaring a variable without a cast. e.g. int i = arr.length; rather than int i = cast(int)arr.length; In general, if the compiler treated giving the foreach variable an explicit type as being a cast, it would make it really easy to screw up and unknowingly give a different type than the actual type of the values and end up with an invisible cast, which could cause subtle bugs. IIRC, the only case where foreach treats giving an explict type as anything like a cast is when you're iterating over a string type, and you give a character type different from the character type of the string. In that case, it actually decodes the string from one Unicode encoding and encodes it in the other. Whether the language should have done that rather than requiring that a library solution be used is debatable (I believe that it far predates Phobos having the Unicode handling that it does now), but at least it can't result in stuff like silent truncation. Worst case, it has a silent performance hit, or you get an unexpected UnicodeException at runtime due to invalid Unicode. - Jonathan M Davis
Re: Deprecation: foreach: loop index implicitly converted from size_t to int
On Friday, 18 January 2019 at 13:29:29 UTC, Adam D. Ruppe wrote: On Friday, 18 January 2019 at 12:27:17 UTC, Michael wrote: This, to be, looks like quite the explicit conversion, no? Yeah, I agree. But the language is silly. I just leave the type out of foreach and explicitly cast it inside the body. Thank you all for the concise explanations and suggestions, I think that's fairly straightforward. I thought perhaps I was doing the sensible thing of dealing with the conversion inside the foreach statement, but I guess not!
Re: Deprecation: foreach: loop index implicitly converted from size_t to int
On Friday, 18 January 2019 at 12:27:17 UTC, Michael wrote: This, to be, looks like quite the explicit conversion, no? Yeah, I agree. But the language is silly. I just leave the type out of foreach and explicitly cast it inside the body.
Re: Deprecation: foreach: loop index implicitly converted from size_t to int
On Friday, 18 January 2019 at 12:27:17 UTC, Michael wrote: Hello all, I am getting this deprecation warning when compiling using DMD64 D Compiler v2.084.0 on Linux. I'm a little unsure what the problem is, however, because the code producing these warnings tends to be of the form: foreach (int i, ref prop; props) This, to be, looks like quite the explicit conversion, no? Does it mean I now have to use to!int(i) to convert the type of i in a foreach now? Thanks, Michael. foreach (int i, ref prop; props) All you need to do is foreach (i, ref prop; props) The reason for the deprecation is that if your array props is > 2GB int can't span the range of indices necessary because it will overflow.
Re: Deprecation: foreach: loop index implicitly converted from size_t to int
On 1/18/19 7:27 AM, Michael wrote:
Hello all,
I am getting this deprecation warning when compiling using DMD64 D
Compiler v2.084.0 on Linux. I'm a little unsure what the problem is,
however, because the code producing these warnings tends to be of the form:
foreach (int i, ref prop; props)
This, to be, looks like quite the explicit conversion, no? Does it mean
I now have to use to!int(i) to convert the type of i in a foreach now?
That's one possibility.
You can avoid to!int by using a mask or a cast:
foreach(_i, ref prop; props)
{
int i = _i & 0x_;
auto i2 = cast(int)_i;
}
It's less than ideal, but the reason is that there is a possibility that
props could have 2^31 or more elements, in which case int will not cut
it. It's forcing you to make that decision that it's OK vs. the compiler
making that assumption. Any time the compiler is throwing away data
without a cast, D tends to require buy in from the developer.
Note that this is much more of a problem with smaller types (short or
byte), but it would be inconsistent not to also flag int as problematic.
I would recommend just using foreach(i, ref prop; props) and casting
only where it's absolutely necessary.
-Steve
Deprecation: foreach: loop index implicitly converted from size_t to int
Hello all, I am getting this deprecation warning when compiling using DMD64 D Compiler v2.084.0 on Linux. I'm a little unsure what the problem is, however, because the code producing these warnings tends to be of the form: foreach (int i, ref prop; props) This, to be, looks like quite the explicit conversion, no? Does it mean I now have to use to!int(i) to convert the type of i in a foreach now? Thanks, Michael.
