On Tuesday, 12 September 2017 at 01:13:29 UTC, Hasen Judy wrote:
Is this is a common beginner issue? I remember using an earlier version of D some long time ago and I don't remember seeing this concept.

Now, a lot of library functions seem to expect ranges as inputs and return ranges as output.

Even parsing a csv line returns a range. And the funny thing is, once you loop over it, it's done. You've basically consumed it.

For example, I was having some trouble with the api of the std.csv module, so to help me debug, I printed the result of the csv. ok, the result seems good. Now I try to use it, for example:

    auto name = row[1];

And to my surprise there's a runtime error, something about range something something. I don't even remember what the error was. The thing is, it wasn't clear what was going on.

The line was actually more like:

auto some_var = some_function(row[1].some_other_library_method!template_variable);

So because I was calling several library methods on the same line, I thought the problem might have something to do with the range not exactly matching what the library was expecting. I thought maybe row[1] also returned some range instead of a string and that range had something wrong with it.

Well, it turned out that my earlier attempt to print the parsed csv row resulted in the row being "consumed" and now the row is an empty range(!).

Is there a straight forward way to convert a Range to a list other than manually doing a foreach?

    string[] items;
    foreach(item; someRangeThing) {
        items ~= item;
    }

I feel like that is a bit of an overkill.

if `range.save` works use that, otherwise

`range.dup` will duplicate the range

or `range.array` (from std.array) will enumerate the range into an array (which is pretty much the same as your solution above.

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