Class: Prelude::Lambda

Inherits:
Proc
  • Object
show all
Defined in:
lib/prelude/lambda.rb

Overview

$Id: lambda.rb 34 2007-10-23 21:38:09Z prelude $

Somewhat extended version of Ruby’s native lambda/Proc that defines all needed methods. We probably can get away with modifying the Proc class, but this approach seems safer.

Instance Method Summary collapse

Constructor Details

#initialize(&block) ⇒ Lambda

Returns a new instance of Lambda.



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# File 'lib/prelude/lambda.rb', line 32

def initialize(&block)
  Proc.new(&block)
end

Instance Method Details

#*(right) ⇒ Object 



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# File 'lib/prelude/lambda.rb', line 43

def *(right)
  Lambda.new {|*a| 
    #p "* #{self.inspect} #{right.inspect} #{a.inspect}"

#         req = right.arity
#         if req > 0
#           right_args = a[0..req-1]
#           left_args = a[req..-1]
#         else
#           right_args = a
#           left_args = []
#         end

#         p "right_args #{right_args.inspect}"
#         right_res = right[*right_args]

#         p "right_res #{right_res.inspect}"
#         if req > 0
#           left_args = [right_res] + left_args
#         else
#           left_args = right_res
#         end
#         p "left_args #{left_args.inspect}"
#         self[*left_args]

    # Compact version of the above (delete the above when done!)
    req = right.arity
    if req > 0
      self[*([right[*a[0..req-1]]] + a[req..-1]) ]
    else
      self[*right[*a]]
    end
    
  }
end

#call(*args) ⇒ Object Also known as: [] 



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# File 'lib/prelude/lambda.rb', line 37

def call(*args)
  #p "call #{self.inspect} #{args.inspect} arity #{self.arity}"
  proc_call(*args)
end

#curry(one) ⇒ Object 



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# File 'lib/prelude/lambda.rb', line 79

def curry(one)
  Lambda.new { |*args| self[one, *args] }
end

#proc_call ⇒ Object 



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# File 'lib/prelude/lambda.rb', line 36

alias proc_call call

#uncurry ⇒ Object 



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# File 'lib/prelude/lambda.rb', line 83

def uncurry()
  Lambda.new { |*args| self[args[0]] }
end