Re: Formatted output of range of tuples

[Ali Çehreli via Digitalmars-d-learn]

On 10/08/2014 02:31 PM, bearophile wrote:

 For indexes now there is also enumerate.

 Bye,
 bearophile

Thanks for the tip. std.range.enumerate makes a big difference:

foreach (i, element; MyRange(42).enumerate) {
// ...
}

versus sequence!n and zip:

foreach (i, element; zip(sequence!n, MyRange(42))) {
// ...
}

Ali

Re: Formatted output of range of tuples

[bearophile via Digitalmars-d-learn]

Ali Çehreli:


foreach (i, element; MyRange(42).enumerate) {
// ...
}

versus sequence!n and zip:

foreach (i, element; zip(sequence!n, MyRange(42))) {
// ...
}


But it's better to not use automatic unpacking of tuples. See 
issues 7361 and especially 9817.


Bye,
bearophile

Re: Formatted output of range of tuples

[monarch_dodra via Digitalmars-d-learn]

On Wednesday, 8 October 2014 at 23:28:34 UTC, bearophile wrote:

anonymous:


You can turn the tuples into ranges with `only`:

writef(%(%(%s %)\n%), zip(indexes, source).map!(t = 
only(t.expand)));


This is a nice idea. Expand can probably be replaced by a []. I 
presume this works only if the types inside the tuple are the 
same.


Expand creates returns a TypeTuple though, so it's arguably 
free. [] allocates a dynamic array, so is costly.


On the flip side, only is *entirelly* by value, and carries all 
its arguments. If the tuple is big, then the range can become 
quite big.

Re: Formatted output of range of tuples

[Sag Academy via Digitalmars-d-learn]

On Monday, 13 October 2014 at 09:20:27 UTC, monarch_dodra wrote:

On Wednesday, 8 October 2014 at 23:28:34 UTC, bearophile wrote:

anonymous:


You can turn the tuples into ranges with `only`:

writef(%(%(%s %)\n%), zip(indexes, source).map!(t = 
only(t.expand)));


This is a nice idea. Expand can probably be replaced by a []. 
I presume this works only if the types inside the tuple are 
the same.


Expand creates returns a TypeTuple though, so it's arguably 
free. [] allocates a dynamic array, so is costly.


On the flip side, only is *entirelly* by value, and carries 
all its arguments. If the tuple is big, then the range can 
become quite big.



you are right man.

Formatted output of range of tuples

[antropod via Digitalmars-d-learn]

Hello!

Consider this code:

+++
import std.stdio;
import std.range;
import std.algorithm;

void printIndexedArray1(T, Range)(T[] source, Range indexes)
{
foreach(row; zip(indexes, source))
{
foreach(col; row) {
write(col,  );
}
writeln;
}
}

void printIndexedArray2(T, Range)(T[] source, Range indexes)
{
writef(%(%(%s %)\n%), zip(indexes, source));
}

void main()
{
uint[] data = [17, 30, 48, 140, 10, 01, 126, 138, 140, 3, 501];
printIndexedArray1(data, sequence!n);
printIndexedArray2(data, sequence!n);

}
+++

Looks fairly straightforward. But, the second function causes 
compilation error:


std.format.FormatException@C:\D\dmd2\windows\bin\..\..\src\phobos\std\format.d(2
585): Expected '%s' format specifier for type 'Tuple!(uint, uint)'

Can you help me with that?

Re: Formatted output of range of tuples

[bearophile via Digitalmars-d-learn]

antropod:

Looks fairly straightforward. But, the second function causes 
compilation error:


std.format.FormatException@C:\D\dmd2\windows\bin\..\..\src\phobos\std\format.d(2
585): Expected '%s' format specifier for type 'Tuple!(uint, 
uint)'


Can you help me with that?


Currently the %(%s%) formatting doesn't support tuples as 
sequences of values.


For indexes now there is also enumerate.

Bye,
bearophile

Re: Formatted output of range of tuples

[anonymous via Digitalmars-d-learn]

On Wednesday, 8 October 2014 at 21:21:47 UTC, antropod wrote:

Hello!

Consider this code:

+++
import std.stdio;
import std.range;
import std.algorithm;

void printIndexedArray1(T, Range)(T[] source, Range indexes)
{
foreach(row; zip(indexes, source))
{
foreach(col; row) {
write(col,  );
}
writeln;
}
}

void printIndexedArray2(T, Range)(T[] source, Range indexes)
{
writef(%(%(%s %)\n%), zip(indexes, source));
}

void main()
{
uint[] data = [17, 30, 48, 140, 10, 01, 126, 138, 140, 3, 501];
printIndexedArray1(data, sequence!n);
printIndexedArray2(data, sequence!n);

}
+++

Looks fairly straightforward. But, the second function causes 
compilation error:


std.format.FormatException@C:\D\dmd2\windows\bin\..\..\src\phobos\std\format.d(2
585): Expected '%s' format specifier for type 'Tuple!(uint, 
uint)'


Can you help me with that?


You can turn the tuples into ranges with `only`:

writef(%(%(%s %)\n%), zip(indexes, source).map!(t =
only(t.expand)));

Re: Formatted output of range of tuples

[Ali Çehreli via Digitalmars-d-learn]

On 10/08/2014 02:34 PM, anonymous wrote:

 You can turn the tuples into ranges with `only`:

 writef(%(%(%s %)\n%), zip(indexes, source).map!(t =
 only(t.expand)));

I haven't measured the performance but there is also the following 
automatic expansion of tuple members as slice elements:


... zip(indexes, source).map!(t = [ t ]));

Probably the same thing...

Ali

Re: Formatted output of range of tuples

[antropod via Digitalmars-d-learn]

On Wednesday, 8 October 2014 at 21:34:54 UTC, anonymous wrote:


You can turn the tuples into ranges with `only`:

writef(%(%(%s %)\n%), zip(indexes, source).map!(t =
only(t.expand)));


That works for me, thanks.

By the way my compiler is DMD 2.066.0

Re: Formatted output of range of tuples

[bearophile via Digitalmars-d-learn]

anonymous:


You can turn the tuples into ranges with `only`:

writef(%(%(%s %)\n%), zip(indexes, source).map!(t = 
only(t.expand)));


This is a nice idea. Expand can probably be replaced by a []. I 
presume this works only if the types inside the tuple are the 
same.


Bye,
bearophile