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RCR 273: Enumerable#inject_with

submitted by ummaycoc on Wed Aug 04 2004 07:52:45 AM -0700

Status: pending

Abstract

Just lets you inject with any method that takes a block...

Problem

Blocks are everywhere. Why not inject with anything?

Proposal

I propose adding an inject_with method to Enumerable. This way, things that might not actually be `injectable' can be...

Analysis

This is simple. No clue what to put here.

Implementation

module Enumerable def Enumerable.inject_with(object, sym, id, *args) object.send(sym, *args) {|*values| id = yield id, *values } id end end

Vote for this RCR

Can you give an example or two? I'm not getting what this would do (simple or not :-)

-- David Black

I guess you should use 'enumerator' which is bundled with 1.8.

  object.to_enum(method).inject(init){....}

Using enumerator, you can enumerate over any method, not just inject.

--matz.

For what it can do - this is what I used it for:

  ifile, idir = *[:file?, :directory?].map {|sym|
    Proc.new {|root| inject_with(Find, :find, [], root) {|arr, path|
      FileTest.send(sym, path) ? arr << path : arr
    }}
  }

-- i.e. make procs to find all files and all directories using find. (simpler way to do that?) but it just seemed like a nice add on - but apparently enumerator can work. Is there documentation for enumerator somewhere in English?

You can find enumerator.txt in the ext/enumerator directory in the distribution archive.