procify - Method to proc conversion path

Handy dsl for wrapping methods in procs.

Installation

gem install procify

Usage

1. Basic method to proc conversion

require 'procify'

def foo
  "foo"
end

foo_proc = proc.foo
puts foo_proc.call # => "foo"

2. Method with argument

require 'procify'

def bar argument
  argument * 2
end

bar_proc = proc.bar
puts bar_proc.call 5 # => 10

3. Custom object method to proc conversion

require 'procify'

class Foo
  def baz
    "baz"
  end
end

foo_instance = Foo.new
baz_proc = foo_instance.proc.baz
puts baz_proc.call # => "baz"

4. Argument providing during conversion

require 'procify'

def cur a, b, c: 5
  a + b + c
end

cur_proc = proc.cur(7, c: 5)
puts cur_proc.call(4) # => 16
puts cur_proc.call(3, c: -10) # => 0

5. Unlike using #method, freshest object method version is always called

require 'procify'

def foo
  "foo"
end

a = proc(&method(:foo))
b = proc.foo

p a.call # => "foo"
p b.call # => "foo"

def foo
  "bar"
end

p a.call # => "foo"
p b.call # => "bar"

6. The conversion can be performed even before the actual method is defined

require 'procify'

a = proc(&method(:foo)) # NameError: undefined method `foo'
b = proc.foo # => #<Proc:0x...

def foo
  "foo"
end

p b.call # => "foo"

7. The converted method is insensitive to context changes

require 'procify'

def foo
  "foo"
end

a = proc{ foo }
b = proc.foo

p a.call # => "foo"
p b.call # => "foo"

class Bar
  def foo
    "bar"
  end
end

bar = Bar.new
p bar.instance_exec(&a) # => "bar"
p bar.instance_exec(&b) # => "foo"

8.

require 'procify'

a = 1
b = a.proc + 2
p b.call # => 3
a = 4
p b.call # => 3

9.

require 'procify'

a = []
b = a.proc << 1
b.call
b.call
b.call
p a # => [1, 1, 1]

10.

require 'procify'

a = [1, 2]
second = a.proc[1]
p second.call # => 2
a.unshift 0
p second.call # => 1

11.

require 'procify'

class Foo
  def initialize arg
    @arg = arg
    ObjectSpace.define_finalizer(self, Foo.proc.finalize(arg))
  end

  def self.finalize arg
    p arg
  end
end

foo = Foo.new "foo"
foo = nil
GC.start # => "foo"

Authors

Łukasz Pomietło (oficjalnyadreslukasza@gmail.com)