Class: Proc

Inherits:
Object show all
Defined in:
lib/nano/proc/compose.rb,
lib/nano/proc/%2A.rb,
lib/nano/proc/to_method.rb

Overview

– Thanks dave! ++

Constant Summary collapse

MethodMutexes = 
Hash.new do |hash, key|
  hash[key] = Mutex.new
end

Instance Method Summary collapse

Instance Method Details

#* ⇒ Object 



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# File 'lib/nano/proc/%2A.rb', line 7

alias_method( :*, :compose )

#compose(other) ⇒ Object

Returns a new proc that is the functional compostion of two procs, in order.

a = lambda { |x| x + 4 }
b = lambda { |y| y / 2 }

(a * b).call(4)  #=> 6
(b * a).call(4)  #=> 4

Raises:

  • (ArgumentError) 


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# File 'lib/nano/proc/compose.rb', line 15

def compose(other)
  raise ArgumentError, "arity count mismatch" unless arity == other.arity
  #proc{ |*a| self.call(other.call(*a)) }
  proc{ |*a| self.call(*other.call(*a)) }
end

#to_method(name = nil) ⇒ Object

Creates a local method based on a Proc.



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# File 'lib/nano/proc/to_method.rb', line 15

def to_method(name=nil)
  name ||= "!to_method_temp#{self.id}"
  recv = eval("self", self)
  klass = recv.class
  MethodMutexes[klass => name].synchronize do
    begin
      klass.send(:define_method, name, &self)
      return recv.method(name)
    ensure
      klass.send(:remove_method, name) if not name
    end
  end
end