IntRange

The library provides fold/map* functions for the range of Int numbers avoiding consuming extra memory.

IntRange.foldl/foldr/map/map2 can be used replacement of List Int value which represents certain range of Int values.

This is useful when iterate vast numbers avoiding consuming extra memory.

For example,

      import IntRange (to)
      import IntRange
      Import List

      IntRange.foldl (+) 0 (0 `to` 100000000) -- Can be calculate without consuming extra memory.
      List.foldl (+) 0 [0..100000000] -- Requires memory for the List of Int which length is 100000000.

Both of List.foldl and IntRange.foldl don't consumes call stack, but List.foldl version consumes memory for the list [0..100000000], in the contrast of IntRange.fold requres relatively small constant memory.

You can create range and invert range by functions to and downTo respectedly:

       IntRange.map (\a->a+1) (1 `to` 3) -- [2,3,4]
       IntRange.map (\a->a+1) (3 `downTo` 1) -- [4,3,2]