stdio line-streaming revisited

[Andrei Alexandrescu (See Website For Email)]

kris wrote:
> Andrei Alexandrescu (See Website For Email) wrote:
>> kris wrote:
>>
>>> Andrei Alexandrescu (See Website For Email) wrote:
>>>
>>>> kris wrote:
>>>>
>>>>> Sean Kelly wrote:
>>>>> [snip]
>>>>>
>>>>>> I must be missing something.  Why is the following not acceptable?
>>>>>>
>>>>>>     import tango.io.Console;
>>>>>>
>>>>>>     void main()
>>>>>>     {
>>>>>>         char[] name;
>>>>>>         Cout( "Please enter your name: " ).flush;
>>>>>>         Cin.nextLine( name );
>>>>>>         Cout( "Hello, " )( name )( "!" );
>>>>>>     }
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> There used to be a tango/example like this variation:
>>>>>
>>>>>     import tango.io.Console;
>>>>>
>>>>>     void main()
>>>>>     {
>>>>>         Cout ("Please enter your name: ").flush;
>>>>>         Cout ("Hello, ") (Cin.get);
>>>>>     }
>>>>
>>>>
>>>>
>>>> Ah, also, the last line is translated into:
>>>>
>>>> Cout.opCall("Hello, ").opCall(Cin.get);
>>>>
>>>> D does not specify evaluation order, so the code might end up 
>>>> printing "Hello, " before reading the standard input. It's funny 
>>>> this does not happen exactly because of buffering, but the program 
>>>> has no control over the buffering so it should assume flushing could 
>>>> happen at any time. So the correct code is:
>>>>
>>>> auto name = Cin.get;
>>>> Cout("Hello, ")(name);
>>>
>>>
>>> Well aware of that, thanks. BTW: evaluation order has been clarified 
>>> before, on a similar topic.
>>
>>
>> Is that clarification identical with the one posted by Frits?
>>
>> Andreo
> 
> Walter clarified, a long time ago, that D would evaluate chained-calls 
> from left to right. I suggest you ask Walter?

As long as it's not in the language definition, you can't count on it. I 
think this is a language defect anyhow; I am lobbying Walter to define 
left-to-right order of evaluation in all cases.

Andrei