catflap.org Online Dictionary Query

  full laziness
       
           A transformation, described by
          Wadsworth in 1971, which ensures that subexpressions in a
          function body which do not depend on the function's arguments
          are only evaluated once.  E.g. each time the function
       
          	f x = x + sqrt 4
       
          is applied, (sqrt 4) will be evaluated.  Since (sqrt 4) does
          not depend on x, we could transform this to:
       
          	f x = x + sqrt4
          	sqrt4 = sqrt 4
       
          We have replaced the dynamically created (sqrt 4) with a
          single shared constant which, in a graph reduction system,
          will be evaluated the first time it is needed and then updated
          with its value.
       
          See also fully lazy lambda lifting, let floating.
       
          (1994-11-09)