Re: Creating InputRanges from strings, files etc.

[rikki cattermole via Digitalmars-d-learn]

On 09/11/2018 2:58 AM, Vinay Sajip wrote:

Excuse my ignorance, but from looking at the documentation on std.range and a quick skim of the guides mentioned there near the top, I can't see what the simple way is of creating an InputRange!(ubyte) from strings, files etc. I would have expected to find something in the DLang Tour about this, but couldn't find anything. Please can someone tell me how to do it? Just to be clear, I want to create an object which is an InputRange!(ubyte) and pass that around, rather than e.g. iterate over a string or a file.

TLDR of how to write an input range:

struct MyInputRange {
        ubyte[] input;

        @property {
                ubyte front() {
                        return this.input[0];
                }

                bool empty() {
                        return this.input.length == 0;
                }
        }

        void popFront() {
                this.input = this.input[1 .. $];
        }
}

import std.stdio;

void main() {
    foreach(b; MyInputRange([1, 2, 3])) {
        writeln(b);
    }
}