Proposal for SentinelInputRange

[FG]

On 2013-02-28 17:43, Walter Bright wrote:
> Consider the following code from lexer.c:
>
>     p++;
>     switch (*p)
>
> Written using an InputRange:
>
>     popFront();
>     switch (front)
>
> That code is INVALID. This is why a SentinelInputRange is necessary. You can't
> just use an InputRange in an invalid manner by convention.
>


I do not understand... Why make a special type of InputRange when you can 
achieve exactly that with a normal string with an added extra '\0' at the end 
and then use it without any calls to empty():

while(1) {
     ...
     popFront();
     switch(front) {
         case '\0': return;
         ...
     }
}

Cstrings are a very special case because we know the terminator beforehand and 
the check is trivial CPU-wise.