Headstrict

1 definition found

From The Free On-line Dictionary of Computing (27 SEP 03) [foldoc]:

  head-strict
       
           A head-strict function will not necessarily evaluate
          every {cons} cell of its (list) argument, but whenever it does
          evaluate a cons cell it will also evaluate the element in the
          head of that cell.  An example of a head-strict function is


       
          	beforeZero :: [Int] -> [Int]
          	beforeZero []     = []
          	beforeZero (0:xs) = []
          	beforeZero (x:xs) = x : beforeZero xs
       
          which returns a list up to the first zero.
       
          This pattern of evaluation is important because it is common
          in functions which operate on a list of inputs.
       
          See also {tail-strict}, {hyperstrict}.
       
          (1995-05-11)