How to find documentation of hard-to-google keywords and symbols

simendsjo simendsjo at gmail.com
Thu Apr 3 09:40:02 PDT 2014


On 04/03/2014 06:31 PM, dnspies wrote:
> On Thursday, 3 April 2014 at 16:10:45 UTC, bearophile wrote:
>> dnspies:
>>
>>> I still don't know where to find documentation for "is" (which I just
>>> found out in another forum post is overloaded for dynamic arrays).
>>> Can users overload the meaning of "is" themselves?
>>
>> Here you find info on the D language:
>> http://dlang.org/spec.html
>>
>> "is" is an operator, so it's an expression, so you find it here:
>> http://dlang.org/expression
>>
>> Bye,
>> bearophile
>
> I don't see where it talks about how to compare dynamic arrays with
> "is".  It says:
>
> The forms of the IsExpression are:
>
> 1.    is ( Type )
> ...
> 2.    is ( Type : TypeSpecialization )
> ...
> 3.    is ( Type == TypeSpecialization )
> ...
> 4.    is ( Type Identifier )
> ...
> 5.    is ( Type Identifier : TypeSpecialization )
> ...
> 6.    is ( Type Identifier == TypeSpecialization )
> ...
> 7.    is ( Type : TypeSpecialization , TemplateParameterList )
> is ( Type == TypeSpecialization , TemplateParameterList )
> is ( Type Identifier : TypeSpecialization , TemplateParameterList )
> is ( Type Identifier == TypeSpecialization , TemplateParameterList )
> ...
>
> This doesn't explain "a is b" where a and b are both dynamic arrays.

`a is b` is called the "Identity expressions" and is very different from 
the "is expression".
http://dlang.org/expression.html#IdentityExpression


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