I write a function with Lambda expression + safe + pure wich do same (close) as countUntil

http://www.dpaste.dzfl.pl/63d03540

but i fail to use lambda expression into my function. I try by two way
- alias this pred … (to get a default lambda)
- function(…) pred

both way i fail, could you take a look to code please.

Goal is to get a pure and safe function

thanks

On 11/30/2013 05:53 PM, bioinfornatics wrote:

> I write a function with Lambda expression + safe + pure wich do same
> (close) as countUntil
>
> http://www.dpaste.dzfl.pl/63d03540
>
> but i fail to use lambda expression into my function. I try by two way
> - alias this pred … (to get a default lambda)
> - function(…) pred
>
> both way i fail, could you take a look to code please.
>
> Goal is to get a pure and safe function
>
> thanks

The obvious problem in the code is the fact that although the intent and the lambda expression itself is written to take two parameters, the lambda is called without any arguments:

1) The default lambda takes two parameters:

  auto search( alias pred = (a,b) => a == b, R,T,S=T)( const ref R toSearch, in T toMatch ) pure

2) and the provided lambda takes two parameters:

	assert( arrStruct.search!( (a,b) => a.id == b )( 8uL ) == 7 );

3) However, the call itself takes no arguments:

              if( pred() ){

So, I would start with that call to debug and pass the two arguments that are appropriate (toSearch.front and toMatch, perhaps?)

Ali

On Sunday, 1 December 2013 at 08:22:41 UTC, Ali Çehreli wrote:
> On 11/30/2013 05:53 PM, bioinfornatics wrote:
>
> > I write a function with Lambda expression + safe + pure wich
> do same
> > (close) as countUntil
> >
> > http://www.dpaste.dzfl.pl/63d03540
> >
> > but i fail to use lambda expression into my function. I try
> by two way
> > - alias this pred … (to get a default lambda)
> > - function(…) pred
> >
> > both way i fail, could you take a look to code please.
> >
> > Goal is to get a pure and safe function
> >
> > thanks
>
> The obvious problem in the code is the fact that although the intent and the lambda expression itself is written to take two parameters, the lambda is called without any arguments:
>
> 1) The default lambda takes two parameters:
>
>   auto search( alias pred = (a,b) => a == b, R,T,S=T)( const ref R toSearch, in T toMatch ) pure
>
> 2) and the provided lambda takes two parameters:
>
> 	assert( arrStruct.search!( (a,b) => a.id == b )( 8uL ) == 7 );
>
> 3) However, the call itself takes no arguments:
>
>               if( pred() ){
>
> So, I would start with that call to debug and pass the two arguments that are appropriate (toSearch.front and toMatch, perhaps?)
>
> Ali

Thanks Ali,

that works now, i was close. http://www.dpaste.dzfl.pl/63d03540