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

[dnspies]

On Thursday, 3 April 2014 at 16:39:02 UTC, simendsjo wrote:
> 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

Oh sorry.  I wouldn't have guessed there would be two different 
areas of the page dealing with different uses of the "is" 
keyword.  And it's not something I can search, because just 
searching the word "is" isn't much help.

What about Tuple.  I try to use a Tuple in my code, but get:

source/app.d(10): Error: template instance Tuple!(int, int) 
template 'Tuple' is not defined

So I google "dlang Tuple" to find out which module I can find it 
in.  The first link I get "http://dlang.org/tuple.html" has all 
this great information on how to construct and use tuples... 
except it fails to mention which module the standard tuple 
definition is in (anywhere on the entire page).

Let's look at the list of D standard modules.  Searching the page 
for "tuple" reveals std.typetuple which seems promising.  Nope, 
no Tuple objects here...

Does no one else see a need for an ALPHABETICAL listing of 
functions and keywords?

In my mind, the problems with navigating the documentation is a 
HUGE barrier to using D effectively.