From: "charliesome (Charlie Somerville)" <charlie@...>
Date: 2012-12-17T14:43:25+09:00
Subject: [ruby-core:50936] [ruby-trunk - Feature #7580][Open] Range translation


Issue #7580 has been reported by charliesome (Charlie Somerville).

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Feature #7580: Range translation
https://bugs.ruby-lang.org/issues/7580

Author: charliesome (Charlie Somerville)
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 


=begin
I would like to propose the (({#+})) and (({#-})) methods on (({Range})).

These would be useful for translating ranges - for example, given a range where the endpoints are 1-indexed, the range could be translated by 1 in the negative direction to use in (({Array#[]})).

Instead of doing a syntactically-bulky manual translation like so:

  ary[(range.begin - 1)..(range.end - 1)]

(({Range#-})) could be used instead:

  ary[range - 1]

The translation methods would not handle certain endpoint types specially, they would just pass the call on.

Here's an example implementation in Ruby:

  class Range
    def +(other)
      Range.new(self.begin + other, self.end + other, exclude_end?)
    end

    def -(other)
      Range.new(self.begin - other, self.end - other, exclude_end?)
    end
  end

=end


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