Smap

Choose the version you want to view.

Current version:Version message:

Program created.

Click on a tag to show all related programs.

curry functional logic functional_pattern

Click on the badge to open the comment window for viewing and writing comments.

No comments yet.

Created by mh on April 9, 2014

0 users favorited this

Description: Solving Dijkstra's Dutch National Flag problem with functional patterns in Curry

Source code (Latest version):

------------------------------------------------------------------------------
-- Example for the extension of Curry with functional patterns as described in:
--
-- Sergio Antoy, Michael Hanus:
-- Declarative Programming with Function Patterns
-- Proceedings of the International Symposium on Logic-based Program Synthesis
-- and Transformation (LOPSTR'05), Springer LNCS 3901, pp. 6-22
------------------------------------------------------------------------------

-- Dijsktra's Dutch National Flag problem with functional patterns

data Color = Red | White | Blue

solve (x++[White]++y++[Red  ]++z) = solve (x++[Red]++y++[White]++z)
solve (x++[Blue ]++y++[Red  ]++z) = solve (x++[Red]++y++[Blue]++z)
solve (x++[Blue ]++y++[White]++z) = solve (x++[White]++y++[Blue]++z)
solve flag | isDutchFlag flag = flag
 where isDutchFlag (uni Red ++ uni White ++ uni Blue) = success

uni _ = []
       uni color = color : uni color

main = solve [White,Red,White,Blue,Red,Blue,White]

--------------------------------------------------------------------------------

Options

Versions

1 version

Tags

4 tags

Comments

0 comments »

Dijkstra's Dutch National Flag Problem

implemented in Curry