Re: block file reads and lazy utf-8 decoding

[Jon D via Digitalmars-d-learn]

On Thursday, 10 December 2015 at 00:36:27 UTC, Jon D wrote:
Question I have is if there is a better way to do this. For 
example, a different way to construct the lazy 
'decodeUTF8Range' rather than writing it out in this fashion.

A further thought - The decodeUTF8Range function is basically 
constructing a lazy wrapper range around decodeFront, which is 
effectively combining a 'front' and 'popFront' operation. So 
perhaps a generic way to compose a wrapper for such functions.


auto decodeUTF8Range(Range)(Range charSource)
    if (isInputRange!Range && is(Unqual!(ElementType!Range) == 
char))
{
    static struct Result
    {
        private Range source;
        private dchar next;

        bool empty = false;
        dchar front() @property { return next; }
        void popFront() {
            if (source.empty) {
                empty = true;
                next = dchar.init;
            } else {
                next = source.decodeFront;
            }
        }
    }
    auto r = Result(charSource);
    r.popFront;
    return r;
}