How do I persuade partial to tie itself to the appropriate overload?
I have:

alias bars=partial!(slurpBars!BarType,filename,startDate,endDate);

where there are two overloads of slurpBars:

SomeBar[] slurpBars(SomeBar)(string filename,string datasetName, typeof(SomeBar.date) startDate, typeof(SomeBar.date) endDate)
SomeBar[] slurpBars(SomeBar)(hid_t filehandle,string datasetName, typeof(SomeBar.date) startDate, typeof(SomeBar.date) endDate)

And I receive the following error:
 Error: template kprop.marketdata.retrievebars.slurpBars matches more than one template declaration:

Thanks.


Laeeth.

On Sunday, 4 October 2015 at 15:45:55 UTC, Laeeth Isharc wrote:
> How do I persuade partial to tie itself to the appropriate overload?
> I have:
>
> alias bars=partial!(slurpBars!BarType,filename,startDate,endDate);
>
> where there are two overloads of slurpBars:
>
> SomeBar[] slurpBars(SomeBar)(string filename,string datasetName, typeof(SomeBar.date) startDate, typeof(SomeBar.date) endDate)
> SomeBar[] slurpBars(SomeBar)(hid_t filehandle,string datasetName, typeof(SomeBar.date) startDate, typeof(SomeBar.date) endDate)
>
> And I receive the following error:
>  Error: template kprop.marketdata.retrievebars.slurpBars matches more than one template declaration:
>
> Thanks.
>
>
> Laeeth.

As far as I can see std.functional.partial only does one argument at a time.

bars=partial!(partial!(partial!(slurpBars!BarType, filename), startDate), endDate);

or maybe, I'm not sure, but maybe you can do:

bars=partial!(slurpBars!BarType, AliasSeq!(filename, startDate, endDate));

If you find you really need to manually mess with overloads, use http://dlang.org/traits.html#getOverloads. You may have to wrap it in AliasSeq in some situations due to grammar/parser constraints.

On Sunday, 4 October 2015 at 16:37:34 UTC, John Colvin wrote:
> On Sunday, 4 October 2015 at 15:45:55 UTC, Laeeth Isharc wrote:
>> How do I persuade partial to tie itself to the appropriate overload?
>> I have:
>>
>> alias bars=partial!(slurpBars!BarType,filename,startDate,endDate);
>>
>> where there are two overloads of slurpBars:
>>
>> SomeBar[] slurpBars(SomeBar)(string filename,string datasetName, typeof(SomeBar.date) startDate, typeof(SomeBar.date) endDate)
>> SomeBar[] slurpBars(SomeBar)(hid_t filehandle,string datasetName, typeof(SomeBar.date) startDate, typeof(SomeBar.date) endDate)
>>
>> And I receive the following error:
>>  Error: template kprop.marketdata.retrievebars.slurpBars matches more than one template declaration:
>>
>> Thanks.
>>
>>
>> Laeeth.
>
> As far as I can see std.functional.partial only does one argument at a time.
>
> bars=partial!(partial!(partial!(slurpBars!BarType, filename), startDate), endDate);
>
> or maybe, I'm not sure, but maybe you can do:
>
> bars=partial!(slurpBars!BarType, AliasSeq!(filename, startDate, endDate));
>
> If you find you really need to manually mess with overloads, use http://dlang.org/traits.html#getOverloads. You may have to wrap it in AliasSeq in some situations due to grammar/parser constraints.


Thanks, John.  I will give that a try.


Laeeth.

On Sunday, 4 October 2015 at 16:37:34 UTC, John Colvin wrote:
> On Sunday, 4 October 2015 at 15:45:55 UTC, Laeeth Isharc wrote:
>> How do I persuade partial to tie itself to the appropriate overload?
---
> As far as I can see std.functional.partial only does one argument at a time.
>
> bars=partial!(partial!(partial!(slurpBars!BarType, filename), startDate), endDate);
>
> or maybe, I'm not sure, but maybe you can do:
>
> bars=partial!(slurpBars!BarType, AliasSeq!(filename, startDate, endDate));
>
> If you find you really need to manually mess with overloads, use http://dlang.org/traits.html#getOverloads. You may have to wrap it in AliasSeq in some situations due to grammar/parser constraints.
fwiw - still doesn't work (whether I use alias or auto, trying each of your solutions).  I'll look at getOverloads.


Laeeth.

On Sunday, 4 October 2015 at 17:17:14 UTC, Laeeth Isharc wrote:
> On Sunday, 4 October 2015 at 16:37:34 UTC, John Colvin wrote:
>> On Sunday, 4 October 2015 at 15:45:55 UTC, Laeeth Isharc wrote:
>>> How do I persuade partial to tie itself to the appropriate overload?
> ---
>> As far as I can see std.functional.partial only does one argument at a time.
>>
>> bars=partial!(partial!(partial!(slurpBars!BarType, filename), startDate), endDate);
>>
>> or maybe, I'm not sure, but maybe you can do:
>>
>> bars=partial!(slurpBars!BarType, AliasSeq!(filename, startDate, endDate));
>>
>> If you find you really need to manually mess with overloads, use http://dlang.org/traits.html#getOverloads. You may have to wrap it in AliasSeq in some situations due to grammar/parser constraints.
> fwiw - still doesn't work (whether I use alias or auto, trying each of your solutions).  I'll look at getOverloads.

How do I distinguish between two overloads that return the same type but have different arguments?  It looks like getOverloads only deals with cases where the return type is different, judging by the docs.

On Sunday, 4 October 2015 at 18:08:55 UTC, Laeeth Isharc wrote:
> On Sunday, 4 October 2015 at 17:17:14 UTC, Laeeth Isharc wrote:
>> On Sunday, 4 October 2015 at 16:37:34 UTC, John Colvin wrote:
>>> On Sunday, 4 October 2015 at 15:45:55 UTC, Laeeth Isharc wrote:
>>>> How do I persuade partial to tie itself to the appropriate overload?
>> ---
>>> As far as I can see std.functional.partial only does one argument at a time.
>>>
>>> bars=partial!(partial!(partial!(slurpBars!BarType, filename), startDate), endDate);
>>>
>>> or maybe, I'm not sure, but maybe you can do:
>>>
>>> bars=partial!(slurpBars!BarType, AliasSeq!(filename, startDate, endDate));
>>>
>>> If you find you really need to manually mess with overloads, use http://dlang.org/traits.html#getOverloads. You may have to wrap it in AliasSeq in some situations due to grammar/parser constraints.
>> fwiw - still doesn't work (whether I use alias or auto, trying each of your solutions).  I'll look at getOverloads.
>
> How do I distinguish between two overloads that return the same type but have different arguments?  It looks like getOverloads only deals with cases where the return type is different, judging by the docs.

getOverloads should give you all the overloads of a function, whether they return the same or different types.  The example in the docs just happens to have different types.

In general, return types are not considered when talking about overloads. For example, two functions that take the same arguments but have different return types are not overloaded, they are in conflict.

On Sunday, 4 October 2015 at 18:24:08 UTC, John Colvin wrote:
> On Sunday, 4 October 2015 at 18:08:55 UTC, Laeeth Isharc wrote:
>> On Sunday, 4 October 2015 at 17:17:14 UTC, Laeeth Isharc wrote:
>>> On Sunday, 4 October 2015 at 16:37:34 UTC, John Colvin wrote:
>>>> On Sunday, 4 October 2015 at 15:45:55 UTC, Laeeth Isharc wrote:
>>>>> How do I persuade partial to tie itself to the appropriate overload?
>>> ---
>>>> As far as I can see std.functional.partial only does one argument at a time.
>>>>
>>>> bars=partial!(partial!(partial!(slurpBars!BarType, filename), startDate), endDate);
>>>>
>>>> or maybe, I'm not sure, but maybe you can do:
>>>>
>>>> bars=partial!(slurpBars!BarType, AliasSeq!(filename, startDate, endDate));
>>>>
>>>> If you find you really need to manually mess with overloads, use http://dlang.org/traits.html#getOverloads. You may have to wrap it in AliasSeq in some situations due to grammar/parser constraints.
>>> fwiw - still doesn't work (whether I use alias or auto, trying each of your solutions).  I'll look at getOverloads.
>>
>> How do I distinguish between two overloads that return the same type but have different arguments?  It looks like getOverloads only deals with cases where the return type is different, judging by the docs.
>
> getOverloads should give you all the overloads of a function, whether they return the same or different types.  The example in the docs just happens to have different types.
>
> In general, return types are not considered when talking about overloads. For example, two functions that take the same arguments but have different return types are not overloaded, they are in conflict.

Thanks for this.  The only problem then is how to manipulate what getOverloads returns.  (No need to do this now as it's not worth it - I just wanted to try using partial if it wasn't too much work.  easier just to make an alternate declaration with the type in its name).

Is this not a bug in the implementation of partial?

import std.functional;
import std.stdio;

void bish(T)(string arg, string barg)
{
	writefln("bishs: %s, %s",arg,barg,to!T);
}
void bish(T)(int argi, string barg)
{
	writefln("bishi: %s, %s",argi,barg.to!T);
}

void main(string[] args)
{
	alias b=partial!(bish!string,"hello"); // this line does not compile
	alias c=partial!(b,"therex");
	b("there");
	c();
}

[laeeth@engine marketdata]$ dmd partial.d
partial.d(15): Error: template partial.bish matches more than one template declaration:
partial.d(4):     bish(T)(string arg, string barg)
and
partial.d(8):     bish(T)(int argi, string barg)


partial knows which overload to call - I told it!

it works fine without templated arguments.  so the following works fine:

import std.functional;
import std.stdio;

void bish(string arg, string barg)
{
	writefln("bishs: %s, %s",arg,barg);
}
void bish(int argi, string barg)
{
	writefln("bishi: %s, %s",argi,barg);
}

void main(string[] args)
{
	alias b=partial!(bish,"hello");
	alias c=partial!(b,"therex");
	b("there");
	c();
}

On Sunday, 4 October 2015 at 19:12:51 UTC, Laeeth Isharc wrote:
> On Sunday, 4 October 2015 at 18:24:08 UTC, John Colvin wrote:
>> On Sunday, 4 October 2015 at 18:08:55 UTC, Laeeth Isharc wrote:
>>> On Sunday, 4 October 2015 at 17:17:14 UTC, Laeeth Isharc wrote:
>>>> On Sunday, 4 October 2015 at 16:37:34 UTC, John Colvin wrote:
>>>>> On Sunday, 4 October 2015 at 15:45:55 UTC, Laeeth Isharc wrote:
>>>>>> How do I persuade partial to tie itself to the appropriate overload?
>>>> ---
>>>>> As far as I can see std.functional.partial only does one argument at a time.
>>>>>
>>>>> bars=partial!(partial!(partial!(slurpBars!BarType, filename), startDate), endDate);
>>>>>
>>>>> or maybe, I'm not sure, but maybe you can do:
>>>>>
>>>>> bars=partial!(slurpBars!BarType, AliasSeq!(filename, startDate, endDate));
>>>>>
>>>>> If you find you really need to manually mess with overloads, use http://dlang.org/traits.html#getOverloads. You may have to wrap it in AliasSeq in some situations due to grammar/parser constraints.
>>>> fwiw - still doesn't work (whether I use alias or auto, trying each of your solutions).  I'll look at getOverloads.
>>>
>>> How do I distinguish between two overloads that return the same type but have different arguments?  It looks like getOverloads only deals with cases where the return type is different, judging by the docs.
>>
>> getOverloads should give you all the overloads of a function, whether they return the same or different types.  The example in the docs just happens to have different types.
>>
>> In general, return types are not considered when talking about overloads. For example, two functions that take the same arguments but have different return types are not overloaded, they are in conflict.
>
> Thanks for this.  The only problem then is how to manipulate what getOverloads returns.  (No need to do this now as it's not worth it - I just wanted to try using partial if it wasn't too much work.  easier just to make an alternate declaration with the type in its name).
>
> Is this not a bug in the implementation of partial?
>
> import std.functional;
> import std.stdio;
>
> void bish(T)(string arg, string barg)
> {
> 	writefln("bishs: %s, %s",arg,barg,to!T);
> }
> void bish(T)(int argi, string barg)
> {
> 	writefln("bishi: %s, %s",argi,barg.to!T);
> }
>
> void main(string[] args)
> {
> 	alias b=partial!(bish!string,"hello"); // this line does not compile
> 	alias c=partial!(b,"therex");
> 	b("there");
> 	c();
> }
>
> [laeeth@engine marketdata]$ dmd partial.d
> partial.d(15): Error: template partial.bish matches more than one template declaration:
> partial.d(4):     bish(T)(string arg, string barg)
> and
> partial.d(8):     bish(T)(int argi, string barg)
>
>
> partial knows which overload to call - I told it!

The problem happens before partial. Something like

alias b = bish!string;

is an error, because it matches both templates. For some reason if you call it directly, e.g.

bish!string("","");

that's ok, but I have no idea why.


What you can do, is this:

template bish(T)
{
	void bish(string arg, string barg)
	{
		writefln("bishs: %s, %s",arg,barg.to!T);
	}
	void bish(int argi, string barg)
	{
		writefln("bishi: %s, %s",argi,barg.to!T);
	}
}

which is just a template containing an overload set, which is no problem.

Or:

void bish0(T)(string arg, string barg)
{
	writefln("bishs: %s, %s",arg,barg.to!T);
}
void bish1(T)(int argi, string barg)
{
	writefln("bishi: %s, %s",argi,barg.to!T);
}

alias bishStr = bish0!string;
alias bishStr = bish1!string;

void main(string[] args)
{
	alias b=partial!(bishStr,"hello");
	alias c=partial!(b,"therex");
	b("there");
	c();
}

Or:

void bish0(T)(string arg, string barg)
{
	writefln("bishs: %s, %s",arg,barg.to!T);
}
void bish1(T)(int argi, string barg)
{
	writefln("bishi: %s, %s",argi,barg.to!T);
}

template bish(T)
{
	alias tmp = bish0!T;
	alias tmp = bish1!T;
	alias bish = tmp;
}

void main(string[] args)
{
	alias b=partial!(bish!string, "hello");
	alias c=partial!(b,"therex");
	b("there");
	c();
}

On Sunday, 4 October 2015 at 20:26:51 UTC, John Colvin wrote:
> template bish(T)
> {
> 	alias tmp = bish0!T;
> 	alias tmp = bish1!T;
> 	alias bish = tmp;
> }

https://issues.dlang.org/show_bug.cgi?id=15156

On Sunday, 4 October 2015 at 20:34:53 UTC, John Colvin wrote:
> On Sunday, 4 October 2015 at 20:26:51 UTC, John Colvin wrote:
>> template bish(T)
>> {
>> 	alias tmp = bish0!T;
>> 	alias tmp = bish1!T;
>> 	alias bish = tmp;
>> }
>
> https://issues.dlang.org/show_bug.cgi?id=15156

Thanks very much, for both John.


Laeeth.