From: sawadatsuyoshi@... Date: 2020-04-26T18:51:49+00:00 Subject: [ruby-core:98071] [Ruby master Feature#16818] Rename `Range#%` to `Range#/` Issue #16818 has been updated by sawa (Tsuyoshi Sawada). zverok (Victor Shepelev) wrote in #note-4: > I'd say that `(5..14) / 3` reads definitely like "split the range into 3 parts" (expecting, IDK, 3 sub-ranges or jumps over `(14-5) / 3` spans). x / y reads "divide x by y", not "divide x into y parts". Following this, `(5..14) / 3` divides `5..14` by `3`, yielding the quotient sets `[5, 6, 7]`, `[8, 9, 10]`, `[11, 12, 13]`, and `[14]`. Iterating over the those quotient sets, taking the representative element from each set gives, `5, 8, 11, 14`. If you don't know what a quotient set is, please take a look at the link I have provided. ---------------------------------------- Feature #16818: Rename `Range#%` to `Range#/` https://bugs.ruby-lang.org/issues/16818#change-85298 * Author: sawa (Tsuyoshi Sawada) * Status: Open * Priority: Normal ---------------------------------------- `Range#%` was introduced as an alias of `Range#step` by 14697, but it is counter-intuitive and confusing. Iteration in the following: ```ruby ((5..14) % 3).each{|i| p i} #>> 5 #>> 8 #>> 11 #>> 14 ``` is not based on `x % y` in any sense. In fact, actually applying `% 3` to the selected elements returns a unique value `2`, and it is not obvious how this is related to the iteration. ```ruby [5, 8, 11, 14].map{|i| i % 3} # => [2, 2, 2, 2] ``` Rather, the concept seems to be based on `/`. Applying `/ 3` to the relevant elements returns a sequence `1, 2, 3, 4`. ```ruby [5, 8, 11, 14].map{|i| i / 3} # => [1, 2, 3, 4] ``` Hence, `(5..14).step(3)` can be interpreted like this: Iterate over the [equivalence class](https://en.wikipedia.org/wiki/Equivalence_class) (quotient set) of range `5..14` yielded by `/ 3`. Notice that the number of elements in `[5, 8, 11, 14]` is 4, which is `(14 - 5 + 1) / 3.0).ceil`, but is not related to `%`. So I propose that the alias of `Range#step` should be `Range#/`, and `Range#%` should be deprecated as soon as possible before its use accumulates: ```ruby ((5..14) / 3).each{|i| p i} #>> 5 #>> 8 #>> 11 #>> 14 ``` --- P.S. And if `Range#%` were to be introduced at all, I would rather expect it to behave like the following: ```ruby ((5..14) % 3).each{|i| p i} #>> 5 #>> 6 #>> 7 ``` which is why I claimed above that the current `Range#%` is confusing. -- https://bugs.ruby-lang.org/ Unsubscribe: