Issue #20953 has been updated by byroot (Jean Boussier).
Do we have a lot of those, and what’s the reasoning/use cases behind this?
Things like `#dig`, so that you can traverse a tree of mixed Hash/Array with some sort of "path" argument. Either way, I see pros and cons to both behavior, so it's not for me to decide, it's up to @matz. The issue though is the release is imminent and the next developer meeting is scheduled for January. So if you wish to change this before the release you'll have to ping @matz on Twitter or something for him to make a decision in time. ---------------------------------------- Feature #20953: Array#fetch_values vs #values_at protocols https://bugs.ruby-lang.org/issues/20953#change-111026 * Author: zverok (Victor Shepelev) * Status: Open ---------------------------------------- I believe that the user might expect `#fetch_values` to be a stricter version of `#values_at`, confirming to the same protocol for arguments. But the current implementation for `#fetch_values` is simpler: ```ruby [1, 2, 3, 4, 5].values_at(0, 3..4) #=> [1, 4, 5] [1, 2, 3, 4, 5].fetch_values(0, 3..4) # TypeError: in 'Array#fetch': no implicit conversion of Range into Integer ``` I believe aligning the implementations would lessen confusion (even if it makes `#fetch_values` implementation somewhat less trivial). The practical example of usefulness: ```ruby HEADERS = %w[Name Department] def table_headers(rows) HEADERS.fetch_values(...rows.map(&:size).max) { '<unknown'> } # Or, alternatively: # HEADERS.fetch_values(...rows.map(&:size).max) { raise ArgumentError, "No header defined for column #{it + 1}" } end table_headers([ ['John'], ['Jane'], ]) #=> ["Name"] table_headers([ ['John'], ['Jane', 'Engineering'], ]) #=> ["Name", "Department"] table_headers([ ['John', 'Accounting', 'Feb 24'], ['Jane', 'Engineering'], ]) #=> ["Name", "Department", "<unknown>"] # or ArgumentError No header defined for column 3 ``` (Obviously, we can use `fetch_values(*(0...max_row_size))` as an argument, but it feels like an unjustified extra work when `values_at` already can do this.) -- https://bugs.ruby-lang.org/