Re: Subrange type
On 1/28/20 1:55 AM, Herbert wrote: > wow, pragma, pragma was to indicate the type of elements at compile time. > import ... Yes, iota is a Phobos feature, part of a module. > only to declare a subrange type, something so simple and natural Some languages think so. > I could use it in many functions as a parameter type with one single > simple declaration. Sorry for jumping in the conversation like that but no, it's not a subrange type. > It's a pitty. My apologies... Ali
Re: Subrange type
On Monday, 27 January 2020 at 22:05:57 UTC, Ali Çehreli wrote:
On 1/27/20 1:15 PM, Herbert wrote:
On Monday, 27 January 2020 at 20:15:33 UTC, Steven
Schveighoffer wrote:
On 1/27/20 3:06 PM, Herbert wrote:
[...]
D doesn't have a "Range" type like this. But you can use
ranges of different types by typing the literals. Note that D
numeric ranges are always exclusive at the upper end.
e.g.:
ushort(1) .. ushort(6+1)
-Steve
Thank you Steven!
How can I have a function parameter with this type (DiceValue)?
There is also iota() than generates a range:
import std.stdio;
import std.range;
void foo(R)(R range) {
pragma(msg, "Element type: ", ElementType!R);
writefln!"Using as a range:\n%-(%s\n%)"(range);
writeln("Using in a foreach loop:");
foreach (element; range) {
writeln(element);
}
}
void main() {
auto range = iota(ushort(1), ushort(7));
foo(range);
}
The output:
Using as a range:
1
2
3
4
5
6
Using in a foreach loop:
1
2
3
4
5
6
Ali
wow, pragma, import ...
only to declare a subrange type, something so simple and natural
I could use it in many functions as a parameter type with one
single simple declaration.
It's a pitty.
Re: Subrange type
On 1/27/20 1:15 PM, Herbert wrote:
On Monday, 27 January 2020 at 20:15:33 UTC, Steven Schveighoffer wrote:
On 1/27/20 3:06 PM, Herbert wrote:
How can I create a subrange type, for example ushort DiceValue {1 ...
6}?
D doesn't have a "Range" type like this. But you can use ranges of
different types by typing the literals. Note that D numeric ranges are
always exclusive at the upper end.
e.g.:
ushort(1) .. ushort(6+1)
-Steve
Thank you Steven!
How can I have a function parameter with this type (DiceValue)?
There is also iota() than generates a range:
import std.stdio;
import std.range;
void foo(R)(R range) {
pragma(msg, "Element type: ", ElementType!R);
writefln!"Using as a range:\n%-(%s\n%)"(range);
writeln("Using in a foreach loop:");
foreach (element; range) {
writeln(element);
}
}
void main() {
auto range = iota(ushort(1), ushort(7));
foo(range);
}
The output:
Using as a range:
1
2
3
4
5
6
Using in a foreach loop:
1
2
3
4
5
6
Ali
Re: Subrange type
On Mon, Jan 27, 2020 at 09:15:58PM +, Herbert via Digitalmars-d-learn wrote:
[...]
> How can I have a function parameter with this type (DiceValue)?
Just take an integer type and add a contract that enforces range. For
example:
auto myFunc(int diceValue)
in (diceValue >= 1 && diceValue <= 6)
{
// do stuff here
}
T
--
Which is worse: ignorance or apathy? Who knows? Who cares? -- Erich Schubert
Re: Subrange type
On Monday, 27 January 2020 at 20:15:33 UTC, Steven Schveighoffer
wrote:
On 1/27/20 3:06 PM, Herbert wrote:
How can I create a subrange type, for example ushort DiceValue
{1 ... 6}?
D doesn't have a "Range" type like this. But you can use ranges
of different types by typing the literals. Note that D numeric
ranges are always exclusive at the upper end.
e.g.:
ushort(1) .. ushort(6+1)
-Steve
Thank you Steven!
How can I have a function parameter with this type (DiceValue)?
Re: Subrange type
On Monday, 27 January 2020 at 20:06:14 UTC, Herbert wrote:
How can I create a subrange type, for example ushort DiceValue
{1 .. 6}?
Probably the closest you can get is a struct with an invariant:
import std.traits: isOrderingComparable;
struct Subrange(T, T min, T max)
if (isOrderingComparable!T)
{
private T value_ = min;
invariant(min <= value && value <= max);
this(T t) { value_ = t; }
T value() { return value_; }
alias value this;
ref Subrage opAssign(T t) { value_ = t; return this; }
}
Re: Subrange type
On 1/27/20 3:06 PM, Herbert wrote:
How can I create a subrange type, for example ushort DiceValue {1 ... 6}?
D doesn't have a "Range" type like this. But you can use ranges of
different types by typing the literals. Note that D numeric ranges are
always exclusive at the upper end.
e.g.:
ushort(1) .. ushort(6+1)
-Steve
Subrange type
How can I create a subrange type, for example ushort DiceValue {1
.. 6}?
