From: duerst@... Date: 2019-10-22T22:52:04+00:00 Subject: [ruby-core:95483] [Ruby master Feature#16261] Enumerable#each_tuple Issue #16261 has been updated by duerst (Martin D�rst). Dan0042 (Daniel DeLorme) wrote: > It's worth pointing out the desired difference with regards to lambdas a bit more explicitly: > > ```ruby > [1, 2, 3].zip([4, 5, 6]).map(&:+) # ArgumentError (wrong number of arguments (given 0, expected 1)) > [1, 2, 3].zip([4, 5, 6]).each_tuple.map(&:+) # => [5, 7, 9] > ``` What you want to do here is in many other languages done with `zip_with`: ```ruby [1, 2, 3].zip_with([4, 5, 6], :+) # => [5, 7, 9] ``` There is already an issue for this, issue #4539, which is open and waits for Matz's approval. ---------------------------------------- Feature #16261: Enumerable#each_tuple https://bugs.ruby-lang.org/issues/16261#change-82255 * Author: zverok (Victor Shepelev) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- New method proposal. Prototype code: ```ruby module Enumerable def each_tuple return to_enum(__method__) unless block_given? each { |item| yield(*item) } # unpacking possible array into several args end end ``` Supposed documentation/explanation: > For enumerable with Array items, passes all items in the block provided as a separate arguments. t could be useful if the provided block has lambda semantics, e.g. doesn't unpack arguments automatically. For example: ```ruby files = ["README.md", "LICENSE.txt", "Contributing.md"] content = [fetch_readme, fetch_license, fetch_contributing] # somehow make a content for the files files.zip(content).each_tuple(&File.:write) # writes to each file its content ``` > When no block passed, returns enumerator of the tuples: ```ruby [1, 2, 3].zip([4, 5, 6]).each_tuple.map(&:+) # => [5, 7, 9] ``` -- https://bugs.ruby-lang.org/ Unsubscribe: