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Passing a byLine as an argument to InputRange
May 13, 2021
Jeff
May 13, 2021
Adam D. Ruppe
May 13, 2021
Ali Çehreli
May 13, 2021
Ali Çehreli
May 14, 2021
Imperatorn
May 14, 2021
Jeff
May 13, 2021
Gravatar of JeffPosted by JeffReply
Jeff
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I have a class where I'd like to supply it with an InputRange!string. Yet, for the life of me I can't seem to pass to it a File.byLine, even though the documentation states it's an InputRange.

class Foo {
  private InputRange!string source;

  this(InputRange!string s) {
    source = s;
  }

  // do stuff with it
}

new Foo(File("stuff.txt").byLine);

// Error constructor Foo.this(InputRange!string) is not callable using argument types (ByLineImpl!(char, char))

I have to believe this is possible. I'm thinking maybe I need to template the constructor with something like:

this(R)(R s) if (isInputRange!R)

But, then I seem to have 2 problems:

  1. I haven't ensured it's an InputRange!string
  2. I've just punted the problem up a level, because my member variable doesn't work.

Any help appreciated. Thanks!

May 13, 2021
Gravatar of Adam D. RuppePosted by Adam D. Ruppe
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Adam D. Ruppe
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On Thursday, 13 May 2021 at 17:07:51 UTC, Jeff wrote:

>

I have a class where I'd like to supply it with an InputRange!string. Yet, for the life of me I can't seem to pass to it a File.byLine, even though the documentation states it's an InputRange.

byLine is not a range of string. It is a range of mutable char[].

I think byLineCopy yields strings though, try that. And if it doesn't work mabye InputRange!(char[]) or similar might work.

May 13, 2021
Gravatar of Ali ÇehreliPosted by Ali Çehreli
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Ali Çehreli
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On 5/13/21 10:07 AM, Jeff wrote:

> I have a class where I'd like to supply it with an InputRange!string.
> Yet, for the life of me I can't seem to pass to it a File.byLine

As Adam said, your range elements need to be converted to string e.g. with 'text' (the same as to!string). However, you must also create a dynamic InputRange!string object for dynamic polymorphism that InputRange provides. And that's achieved by function inputRangeObject():

import std.range;
import std.stdio;
import std.algorithm;
import std.conv;

class Foo {
  private InputRange!string source;

  this(InputRange!string s) {
    source = s;
  }

  // do stuff with it
}

void main() {
  new Foo(inputRangeObject(File("stuff.txt").byLine.map!text));
}

Ali
May 13, 2021
Gravatar of Ali ÇehreliPosted by Ali Çehreli
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Ali Çehreli
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On 5/13/21 11:29 AM, Ali Çehreli wrote:

> create a dynamic InputRange!string object for dynamic polymorphism that InputRange provides. And that's achieved by function inputRangeObject():

Some examples:


http://ddili.org/ders/d.en/ranges_more.html#ix_ranges_more.polymorphism,%20run-time

Ali
May 14, 2021
Gravatar of JeffPosted by Jeff
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On Thursday, 13 May 2021 at 18:29:08 UTC, Ali Çehreli wrote:
> On 5/13/21 10:07 AM, Jeff wrote:
>
> > I have a class where I'd like to supply it with an
> InputRange!string.
> > Yet, for the life of me I can't seem to pass to it a
> File.byLine
>
> As Adam said, your range elements need to be converted to string e.g. with 'text' (the same as to!string). However, you must also create a dynamic InputRange!string object for dynamic polymorphism that InputRange provides. And that's achieved by function inputRangeObject():
>

Thank you all. I'm up and running. ;-)
May 14, 2021
Gravatar of ImperatornPosted by Imperatorn
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Imperatorn
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On Thursday, 13 May 2021 at 18:31:41 UTC, Ali Çehreli wrote:
> On 5/13/21 11:29 AM, Ali Çehreli wrote:
>
>> create a dynamic InputRange!string object for dynamic polymorphism that InputRange provides. And that's achieved by function inputRangeObject():
>
> Some examples:
>
>
> http://ddili.org/ders/d.en/ranges_more.html#ix_ranges_more.polymorphism,%20run-time
>
> Ali

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