From: "mame (Yusuke Endoh)" <mame@...>
Date: 2012-05-23T00:23:12+09:00
Subject: [ruby-core:45185] [ruby-trunk - Bug #6476][Rejected] Proc unrolls an array even without splat


Issue #6476 has been updated by mame (Yusuke Endoh).

Status changed from Open to Rejected

Hello,

prijutme4ty (Ilya Vorontsov) wrote:
> pr_def(*[1,2,3])  # => [1] + [2,3]

It should be: "1 + [2, 3]"


> Is it right behaviour or such unsplatting is a bug?

It is the spec.  A method and lambda use a strict rule for arguments,
but a proc uses a flexible one: it does not distinguish multiple
arguments from one array argument.

  def foo
    yield 1, 2
  end
  def bar
    yield [1, 2]
  end

  f = proc {|x, y| p x + y }
  foo(&f) #=> 3
  foo(&f) #=> 3

  f.call(1, 2)   #=> 3
  f.call([1, 2]) #=> 3

-- 
Yusuke Endoh <mame@tsg.ne.jp>
----------------------------------------
Bug #6476: Proc unrolls an array even without splat
https://bugs.ruby-lang.org/issues/6476#change-26765

Author: prijutme4ty (Ilya Vorontsov)
Status: Rejected
Priority: Normal
Assignee: 
Category: 
Target version: 
ruby -v: 1.9.3p194


Normal behaviour:

def pr_def(recv,*args)
  puts "#{recv.inspect} + #{args.inspect}"
end
pr_def(*[1,2,3])  # => [1] + [2,3]
pr_def([1,2,3])   # => [1,2,3] + []
pr_def([[1,2,3]]) # => [[1,2,3]] + []

pr_lambda = lambda{|recv,*args| puts "#{recv.inspect} + #{args.inspect}"}
pr_lambda.call(*[1,2,3])  # => [1] + [2,3]
pr_lambda.call([1,2,3])   # => [1,2,3] + []
pr_lambda.call([[1,2,3]]) # => [[1,2,3]] + []


But Proc acts in a different way.

pr_proc = Proc.new{|recv,*args| puts "#{recv.inspect} + #{args.inspect}"}
pr_proc.call(*[1,2,3])   # => 1 + [2,3]
pr_proc.call([1,2,3])    # => 1 + [2,3]
pr_proc.call([[1,2,3]])  # => [1,2,3] + []

Is it right behaviour or such unsplatting is a bug?


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