From: "mame (Yusuke Endoh)" <mame@...>
Date: 2012-03-27T01:55:38+09:00
Subject: [ruby-core:43698] [ruby-trunk - Feature #5129][Assigned] Create a core class "FileArray" and make "ARGF" its instance


Issue #5129 has been updated by mame (Yusuke Endoh).

Status changed from Open to Assigned
Assignee set to matz (Yukihiro Matsumoto)

Hello,

I like the idea, but it requires matz's approval.


> Now when I "p ARGF.class", I get "ARGF.class", so ARGF is an instance of ARGF.class, how meaningless it is.

FYI: In fact, it is meaningful.  You can "exploit" it.

    $ cat a.txt
    foo
    $ cat b.txt
    bar
    $ ruby -e 'p ARGF.class.new("a.txt", "b.txt").read'
    "foo\nbar\n"

I'm not sure if this behavior is the spec, though.

-- 
Yusuke Endoh <mame@tsg.ne.jp>
----------------------------------------
Feature #5129: Create a core class "FileArray" and make "ARGF" its instance
https://bugs.ruby-lang.org/issues/5129#change-25198

Author: yimutang (Joey Zhou)
Status: Assigned
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: 
Target version: 


I suggest to create a class "FileArray" whose instance behaves just like ARGF do.
And I think ARGF should be an instance of FileArray. Now when I "p ARGF.class", I get "ARGF.class", so ARGF is an instance of ARGF.class, how meaningless it is.


FileArray methods:

# create an instance
fa = FileArray.new('a.txt','b.txt','c.txt')

# take many methods from IO
# most methods from ARGF should be instance methods of ARGF 
fa.each {|line| puts line }
fa.realines
fa.filename # current file

# but "argv" not
p fa.file_list # in ARGF, its ARGF.argv, but #argv is not a proper name for FileArray

# ARGV array can be modified, adding new file into it, all replace to a new file list.
# FileArray should add some methods to modify the inner file list.
fa.insert(3,"d.txt")
fa.delete('a.txt')


With FileArray, You can create multiple ARGF-like file arrays simultaneously.

For example, I want to mix two *groups* of files, not two files:

a_files = FileArray.new(*Dir.glob('a*.txt'))
b_files = FileArray.new(*Dir.glob('b*.txt'))

enum_a = a_files.each
enum_b = b_files.each

loop do
 puts enum_a.next
 puts enum_b.next
end


-- 
http://bugs.ruby-lang.org/