The quote is ambiguous. In my experience with Mesa, its range syntax was straightforward, but you do have to decide which kind of range to use when. Was that Dijkstra's point? (Write
[2..length) depending on the situation.) Or maybe I didn't know about or forgot about range mistakes other people made.
The Mesa notation is so memorable that I still use it in comments,
(a..b]. I find it disorienting when others use what I guess is a more recent math notation
[a,b]. That reads as tuples or vectors.
Truthfully, the symmetrical notation
a..b is not great for the asymmetrical half-open interval
[a..b). We can cope, but I anticipate more mistakes than Dijkstra refers to.
(a..b).inclusive() adds a second asymmetry by modifying only one side, using a name that doesn't take sides.
a..=b is an asymmetrical notation for a symmetrical closed interval. (That is, if you read it as an interval. It sure looks like an assignment to me.)
a...b may be OK, but does
1 ... 2 or
1.0 .. 2, or
1 .. 0.2?