I’m currently writing a CLI tool that handles a specific JSON data format. And I also want to give the user to get a slice of the item array of the file. It’s a slice in form of --slice START:END through commandline options. So in example --slice 1:2.
- Should I provide a 0 based index for the access or a 1 based index? In example
--slice 1:2with 0 based index would start with the second element and with 1 based index it would start with the first element. - And would you think its better to have the
ENDto be inclusive or exclusive? In example--slice 1:2would get only one element if its exclusive or it gets two elements if its inclusive.
I know this is all personal taste, but I’m currently just torn between all options and cannot decide. And thought to ask you what you think. Maybe that helps me sorting my own thoughts a bit. Thanks in advance.
I think that I’m going with these approaches. For the ‘0’, I’m now accepting it as the 0 element. Which is not 0 based index, but it really means before the first element. So any slice with an END of 0 is always nothing. Anything that starts at 0 will basically give you as many elements as END points to.
0:is equivalent to:and1:(meaning everything)0is equivalent to0:0and:0(meaning empty)1:0still empty, because it starts after it ended, which reads like “start by 1, give me 0 elements”1:1gives one element, the first, which reads like “start by 1, give me 1 element”I feel confident about this solution. And thanks for everyone here, this was really what I needed. After trying it out in the test data I have, I personally like this model. This isn’t anything surprising, right?
I personally find it easier for non programmers to use a START:LENGTH model.
3:5 is (up to) 5 elements starting at the third.
1:1 is just the first element
Any 0 is invalid
20:2 is elements 20 and 21
It eliminates inclusive/exclusive questions.