资料来源 : Free On-Line Dictionary of Computing

space leak
     
        A data structure which grows bigger, or lives longer, than
        might be expected.  Such unexpected memory use can cause a
        program to require more {garbage collection}s or to run out of
        {heap}.  Space leaks in {functional program}s usually result
        from excessive laziness.  For example, the {Haskell} function
     
        	sum []     = 0
        	sum (x:xs) = x + sum xs
     
        when applied to a list will build a chain of closures for the
        additions and only when it reaches the end of the list will it
        perform the additions and free the storage.  Another example
        is the function
     
        	mean l = sum l / length l
     
        The sum function forces the entire list l to be evaluated and
        built in the heap.  None of it can be garbage collected until
        the length function has consumed it.