资料来源 : Free On-Line Dictionary of Computing

combinator
     
         A function with no {free variables}.  A term is
        either a constant, a variable or of the form A B denoting the
        {application} of term A (a function of one argument) to term
        B.  {Juxtaposition} associates to the left in the absence of
        parentheses.  All combinators can be defined from two basic
        combinators - S and K.  These two and a third, I, are defined
        thus:
     
        	S f g x	= f x (g x)
        	K x y	= x
        	I x	= x		= S K K x
     
        There is a simple translation between {combinatory logic} and
        {lambda-calculus}.  The size of equivalent expressions in the
        two languages are of the same order.
     
        Other combinators were added by {David Turner} in 1979 when he
        used combinators to implement {SASL}:
     
        	B f g x = f (g x)
        	C f g x = f x g
        	S' c f g x = c (f x) (g x)
        	B* c f g x = c (f (g x))
        	C' c f g x = c (f x) g
     
        See {fixed point combinator}, {curried function},
        {supercombinator}s.
     
        (2002-11-03)