On 02.11.19 18:13, Jordan Brown wrote: > Why not only closed intervals?  For integer indices, it > seems like the only difference between closed and open > is adding a +1 to the start or -1 to the end. Or are you > concerned that if end is zero and they want open on the > right, they'd end up with -1 and trigger the "measure > from the end" case? Both actually. Specifically for the (deprecated) range behavior which swaps values if the second one is less than the first value. v = []; for (i = [0:len(v) - 1]) { echo(i = i); } // DEPRECATED: Using ranges of the form [begin:end] with begin value greater than the end value is deprecated. // ECHO: i = -1 // ECHO: i = 0 You already can get around that using [0:1:len(v) - 1] though. But [0:<len(v)] does not seem too bad either. Otherwise it's pretty much simple syntactic sugar, so it's not super critical to have it. After playing a bit with this way to specify the range end, I start to like it. It does give a nice way of reading ranges/slices. [2:<5] start at index 2 and stop at index less than 5 > Maybe always closed on the left and always open on > the right, so if you want different you'd +1 on one > end or the other? I don't think there's a way to do that without breaking existing code. > Adding new syntax is ugly... Why? We should probably try to not add too ugly stuff, but I don't think it's wrong to add things at all. I'd like OpenSCAD to stay very simple to get started, just as it is now. But it needs quite some more features to really grow up. I suspect not everyone will need those features but we want to give it into the hands of people who can build libraries. ciao, Torsten.