Feature #7612

Enumerators take a proc

Added by Perry Smith over 1 year ago. Updated over 1 year ago.

[ruby-core:51099]
Status:Rejected
Priority:Normal
Assignee:-
Category:-
Target version:-

Description

If there is already a clean syntax for this, I apologize. I sure could not find it.

class Foo
def initialize
@inst = 18
end

def meth(a, b)
puts "method #{@inst} #{a} #{b}"
end
end

foo = Foo.new

e = %w{a b c}.eachwithindex
p1 = Proc.new { |a, b| puts "proc #{a} #{b}" }
m2 = foo.method(:meth)
p2 = m2.to_proc

Current Syntax possibilities

e.each { |a, b| puts "direct #{a} #{b}" }
e.each { |a, b| foo.meth(a, b) }
e.each { |a, b| p1.call(a,b) }
e.each { |a, b| m2.call(a,b) }
e.each { |a, b| p2.call(a,b) }

Proposed Addition

e.each(p1) # same as e.each { |a, b| p1.call(a,b) }
e.each(m2) # same as e.each { |a, b| m2.call(a,b) }
e.each(p2) # same as e.each { |a, b| p2.call(a,b) }

In the case of a method or lambda, the arguments are checked and possible errors thrown.

In the case of a proc, the proc "tricks" apply

To add readability, an "apply_to" method could be added:

e.apply_to(p1)

The extra "each" bothers me since the enumerator already has an "each" associated with it.

History

#1 Updated by Thomas Sawyer over 1 year ago

=begin
Use &:

e.each(&p1)
e.each(&m2)
e.each(&p2)
=end

#2 Updated by Marc-Andre Lafortune over 1 year ago

  • Status changed from Open to Rejected

#3 Updated by Anonymous over 1 year ago

Great! I tried something similar but I must have botched it somehow.

Oh.... I bet I tried e(&p1)

On Dec 23, 2012, at 1:15 PM, trans (Thomas Sawyer) wrote:

Issue #7612 has been updated by trans (Thomas Sawyer).

=begin
Use &:

e.each(&p1)
e.each(&m2)
e.each(&p2)
=end


Feature #7612: Enumerators take a proc
https://bugs.ruby-lang.org/issues/7612#change-35034

Author: pedz (Perry Smith)
Status: Open
Priority: Normal
Assignee:
Category:
Target version:

If there is already a clean syntax for this, I apologize. I sure could not find it.

class Foo
def initialize
@inst = 18
end

def meth(a, b)
puts "method #{@inst} #{a} #{b}"
end
end

foo = Foo.new

e = %w{a b c}.eachwithindex
p1 = Proc.new { |a, b| puts "proc #{a} #{b}" }
m2 = foo.method(:meth)
p2 = m2.to_proc

Current Syntax possibilities

e.each { |a, b| puts "direct #{a} #{b}" }
e.each { |a, b| foo.meth(a, b) }
e.each { |a, b| p1.call(a,b) }
e.each { |a, b| m2.call(a,b) }
e.each { |a, b| p2.call(a,b) }

Proposed Addition

e.each(p1) # same as e.each { |a, b| p1.call(a,b) }
e.each(m2) # same as e.each { |a, b| m2.call(a,b) }
e.each(p2) # same as e.each { |a, b| p2.call(a,b) }

In the case of a method or lambda, the arguments are checked and possible errors thrown.

In the case of a proc, the proc "tricks" apply

To add readability, an "apply_to" method could be added:

e.apply_to(p1)

The extra "each" bothers me since the enumerator already has an "each" associated with it.

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

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